Nonequilibrium Sedimentation of Colloids on the Particle Scale
C. Patrick Royall, Joachim Dzubiella, Matthias Schmidt, and Alfons van Blaaderen
We investigate sedimentation of model hard-sphere-like colloidal dispersions confined in horizontal capillaries using laser scanning confocal microscopy, dynamical density functional theory, and Brownian dynamics computer simulations. For homogenized initial states we obtain quantitative agreement o ... [Phys. Rev. Lett. 98, 188304 (2007)] published Thu May 3, 2007.
Anisotropic electric conduction derived from self-organized nanogroove array on Li-doped NiO epitaxial film
Akifumi Matsuda, Shusaku Akiba, Masayasu Kasahara, Takahiro Watanabe, Yasuyuki Akita et al.
The self-assembly formation of straight and periodic nanogroove arrays was carried out on the surface of Li-doped NiO thin films by use of atomic steps on the substrate. The nanostructure was formed by annealing Li-doped NiO (111) epitaxial thin film prepared on an atomically stepped alpha-Al[sub 2] ... [Appl. Phys. Lett. 90, 182107 (2007)] published Wed May 2, 2007.
Deep levels controlling the electrical properties of Fe-implanted GaInP/GaAs
Beatrice Fraboni, Erio Piana, Tiziana Cesca, Andrea Gasparotto, Massimo Longo et al.
The authors investigated the electrical compensation induced by deep levels introduced in metal organic vapor phase epitaxy grown n[sup +]-InGaP/GaAs epitaxial layers by high temperature Fe implantation. The activation of the Fe[sup 2+]-related deep levels has been assessed by current-voltage analys ... [Appl. Phys. Lett. 90, 182106 (2007)] published Wed May 2, 2007.
Copper barrier properties of a low-dielectric-constant organocyclosiloxane prepared by plasma-enhanced polymerization
Takenobu Yoshino, Nobuhiro Hata, Jun Kawahara, and Takamaro Kikkawa
An excellent barrier effect against copper (Cu) ion drift of an organocyclosiloxane (OCS) low-dielectric-constant film is studied by electric measurements. The OCS film, which was formed by plasma-enhanced polymerization, had two kinds of organic groups such as alkyl and vinyl groups extending from ... [Appl. Phys. Lett. 90, 182111 (2007)] published Wed May 2, 2007.
Surface plasmon enhanced diffraction in cholesteric liquid crystals
Wen-Chi Hung, Wood-Hi Cheng, Ming-Shan Tsai, Yi-Chung Juan, I-Min Jiang et al.
The authors report the observation of an enhanced optical diffraction in cholesteric liquid crystals (CLCs) due to the presence of silver nanoparticles. The silver nanoparticles are deposited on the surface of one of the indium tin oxide electrodes of the CLC cell. With the application of a proper v ... [Appl. Phys. Lett. 90, 183115 (2007)] published Wed May 2, 2007.
Lead-free In[sub 2]O[sub 3]-doped (Bi[sub 0.5]Na[sub 0.5])[sub 0.93]Ba[sub 0.07]TiO[sub 3] ceramics synthesized by direct reaction sintering
Tao-Sheng Zhou, Rong-Xia Huang, Xun-Zhong Shang, Fei Peng, Jian-Yong Guo et al.
Lead-free (Bi[sub 0.5]Na[sub 0.5])[sub 0.93]Ba[sub 0.07]TiO[sub 3]x wt %In[sub 2]O[sub 3] ceramics synthesized by direct reaction sintering have been studied. X-ray diffraction reveals that all (Bi[sub 0.5]Na[sub 0.5])[sub 0.93]Ba[sub 0.07]TiO[sub 3]x wt %In[sub 2]O[sub 3] ceramics are of a pero ... [Appl. Phys. Lett. 90, 182903 (2007)] published Wed May 2, 2007.
Photonic crystal effect on light emission from InGaN/GaN multi-quantum-well structures
Keunjoo Kim, Jaeho Choi, Sang Cheol Jeon, Jin Soo Kim, and Hee Mok Lee
Triangular hole arrays with nanoscaled lattice constants of 230 and 460 nm were fabricated on a p-type GaN epitaxial layer grown on an InGaN/GaN multi-quantum-well light emitting diode structure by metal-organic chemical vapor deposition. The hole geometries of dry-etched thin slabs for triangular ... [Appl. Phys. Lett. 90, 181115 (2007)] published Wed May 2, 2007.
Influence of quenching rate on the microstructure and magnetic properties of melt-spun L1[sub 0]-FePt/Fe[sub 2]B nanocomposite magnets
Wei Zhang, Kunio Yubuta, Parmanand Sharma, Akihiro Makino, and Akihisa Inoue
The quenching rate, which is dependent on the surface velocity (V[sub s]) of Cu wheel during melt spinning, has significant influence on the formation of nanocomposite structure in the Fe[sub 52]Pt[sub 32]B[sub 18] melt-spun ribbons. The L1[sub 0]-FePt/Fe[sub 2]B hard magnetic nanocomposite structur ... [J. Appl. Phys. 101, 09K518 (2007)] published Wed May 2, 2007.
An ab initio investigation on the endohedral metallofullerene Gd[sub 3]N--C[sub 80]
M. C. Qian and S. N. Khanna
First-principles electronic structure studies on the ground state geometry and electronic and magnetic properties of bare and hydrogen coated metallofullerene Gd[sub 3]NC[sub 80] have been carried out within a density functional formalism. The correlation effects are incorporated either through a ge ... [J. Appl. Phys. 101, 09E105 (2007)] published Wed May 2, 2007.
Photoluminescence and self-interference in germanium-doped silica films
Y. M. Yang, L. W. Yang, M. Q. Cai, and Paul K. Chu
Germanium-doped silica films were prepared by magnetron cosputtering and postannealing. The photoluminescence properties and their dependence on the Ge contents and annealing temperature were investigated. Our experiments indicate that the observed light emission originates from the neutral oxygen v ... [J. Appl. Phys. 101, 093503 (2007)] published Wed May 2, 2007.
Critical adsorption on nonspherical colloidal particles
S. Kondrat, L. Harnau, and S. Dietrich
We consider a nonspherical colloidal particle immersed in a fluid close to its critical point. The temperature dependence of the corresponding order parameter profile is calculated explicitly. We perform a systematic expansion of the order parameter profile in powers of the local curvatures of the s ... [J. Chem. Phys. 126, 174902 (2007)] published Wed May 2, 2007.
Photoluminescence Study of an Er-Doped Si-Rich SiO[sub x] Film
C. L. Heng, O. H. Y. Zalloum, T. Roschuk, D. Blakie, J. Wojcik et al.
We have studied photoluminescence (PL) from samples of Er-doped Si-rich silicon oxide (SRSO) annealed at 875 degrees C for 1 h in N[sub 2], N[sub 2]+5% H[sub 2] (FG1), Ar+5% H[sub 2] (FG2), and O[sub 2], respectively, or subjected to double-step annealing processes. For the given film composition ... [Electrochem. Solid-State Lett. 10, K20 (2007)] published Wed May 2, 2007.
Tunability and ferroelectric relaxor properties of bismuth strontium titanate ceramics
Wei Chen, Xi Yao, and Xiaoyong Wei
A systemic study was performed on bismuth strontium titanate (Sr[sub 11.5x]Bi[sub x]TiO[sub 3], 0.04<=x<=0.25) ceramics. Dielectric properties were measured from 83 to 373 K at different frequencies. A transformation from relaxor ferroelectrics to relaxor behavior was observed when x>0.10. Both d ... [Appl. Phys. Lett. 90, 182902 (2007)] published Tue May 1, 2007.
Direct writing three-dimensional Ba[sub 2]TiSi[sub 2]O[sub 8] crystalline pattern in glass with ultrashort pulse laser
Ye Dai, Bin Zhu, Jianrong Qiu, Hongliang Ma, Bo Lu et al.
The nonlinear optical crystal Ba[sub 2]TiSi[sub 2]O[sub 8] is induced three-dimensionally inside a glass by a femtosecond pulse laser with 800 nm, 250 kHz, and 150 fs. Micro-Raman and photoluminescence spectra confirm that crystals can grow in the focal point of the laser beam. Continuous crystal ... [Appl. Phys. Lett. 90, 181109 (2007)] published Tue May 1, 2007.
Sellmeier equations for green, yellow, and orange colored HgGa[sub 2]S[sub 4] crystals
Tie-Jun Wang, Zhi-Hui Kang, Hong-Zhi Zhang, Zhi-Shu Feng, Feng-Guang Wu et al.
Modeling and experimental study on phase matching of second harmonic generation in different color HgGa[sub 2]S[sub 4] crystals are carried out. Using the known Sellmeier equations, the dispersion relation with weighting proportionally to short-wavelength boundary of the crystal transparency band is ... [Appl. Phys. Lett. 90, 181913 (2007)] published Tue May 1, 2007.
Second order optical nonlinearity of ZnO/ZnO:Al bilayers deposited on glass by low temperature radio frequency sputtering
F. Michelotti, R. Canali, L. Dominici, A. Belardini, F. Menchini et al.
The authors report on the measurement of the second order nonlinear optical properties of ZnO films deposited by low temperature radio frequency sputtering on ZnO:Al coated glass substrates. They show that ZnO:Al plays a crucial role as a buffer layer for the successive growth of ZnO. The effect of ... [Appl. Phys. Lett. 90, 181110 (2007)] published Tue May 1, 2007.
Enhanced electric field tunable dielectric properties of BaZr[sub x]Ti[sub 1 - x]O[sub 3] relaxor ferroelectrics
Tanmoy Maiti, R. Guo, and A. S. Bhalla
The environmental friendly lead-free perovskite BaZr[sub x]Ti[sub 1x]O[sub 3] (x=0.35, 0.40, and 0.45) relaxor ceramics are developed for the tunable microwave device applications such as tunable filters, phase shifters, antennas, etc. Electric field dependence of dielectric behavior of the ceramic ... [Appl. Phys. Lett. 90, 182901 (2007)] published Tue May 1, 2007.
Photoluminescence properties of Cr[sup 2+]:ZnSe films deposited by radio frequency magnetron cosputtering
N. Vivet, M. Morales, M. Levalois, J. L. Doualan, and R. Moncorge
Cr[sup 2+]:ZnSe films were grown at room temperature by the radio frequency magnetron cosputtering technique. The structural characterization of the films shows that the corresponding films are well crystallized mainly in the cubic zinc-blende structure with strong orientations. Using direct (1850 ... [Appl. Phys. Lett. 90, 181915 (2007)] published Tue May 1, 2007.
Structural and dielectric properties of (Li[sub 0.5]Na[sub 0.5]) doped strontium barium niobate
Md. Ahamad Mohiddon and K. L. Yadav
The alkali (Li[sub 0.5]Na[sub 0.5]) modified strontium barium niobate (SBN) was prepared by a conventional mixed oxide method. X-ray diffraction was carried out to study the phase changes developed in the sample. Quantitative x-ray analysis was also carried out to study the effect of (Li[sub 0.5]Na[ ... [J. Appl. Phys. 101, 094101 (2007)] published Tue May 1, 2007.
Laser-light diffraction studies on the electric-field response of the helical director configuration in smectic-C[sup *] liquid crystals
Michael Krueger and Frank Giesselmann
We report results from laser light diffraction studies on the electric-field-induced dynamic modulation of the helical director configuration of SmC[sup *] liquid crystals. In contrast to what is predicted by common theoretical models for bulk samples, we found no increase of the helix pitch with in ... [J. Appl. Phys. 101, 094102 (2007)] published Tue May 1, 2007.
Investigating microstructure of concentrated suspensions of anisotropic particles under shear by small angle neutron scattering
E. B. Mock and C. F. Zukoski
The microstructure of dense suspensions of anisotropic particles that are ordered at rest is explored under shear as a function of particle anisotropy and shear rate using small angle neutron scattering. For suspensions containing spheres and mildly anisotropic heteronuclear dicolloids, after preshe ... [J. Rheol. 51, 541 (2007)] published Tue May 1, 2007.
Rheology of concentrated granular suspensions undergoing squeeze flow
S. Mascia and D. I. Wilson
This paper reports experimental and modeling work on biaxial extension of three highly filled microcrystalline cellulose suspensions employing squeeze flow with lubricated plates. The squeeze flow data explored both the initial compaction of the material before yield and subsequent flow rate dependa ... [J. Rheol. 51, 493 (2007)] published Tue May 1, 2007.
Shear induced normal stress differences in aqueous foams
Vincent Labiausse, Reinhard Hohler, and Sylvie Cohen-Addad
A finite simple shear deformation of an elastic solid induces unequal normal stresses. This nonlinear phenomenon, known as the Poynting effect, is governed by a universal relation between shear strain and first normal stresses difference, valid for nondissipative isotropic elastic materials. We prov ... [J. Rheol. 51, 479 (2007)] published Tue May 1, 2007.
Shear thickening of an emulsion stabilized with hydrophilic silica particles
Bettina Wolf, Sylvie Lam, Mark Kirkland, and William J. Frith
The flow behavior of particle stabilized oil-in-water emulsions with different dispersed volume fractions was analyzed in steady shear on a rotational rheometer employing a coaxial cylinder geometry. The dispersed phase of the emulsion was a mixture of equal volumes of a polar oil, isopropyl myrista ... [J. Rheol. 51, 465 (2007)] published Tue May 1, 2007.
Quantifying dispersion of layered nanocomposites via melt rheology
J. Vermant, S. Ceccia, M. K. Dolgovskij, P. L. Maffettone, and C. W. Macosko
Rheological measurements are used to compare clay nanocomposites prepared through melt mixing using two different polypropylene matrices. Steady state and transient nonlinear rheological experiments are employed to separate the contributions of flow induced orientation of the tactoids and particulat ... [J. Rheol. 51, 429 (2007)] published Tue May 1, 2007.
The bulk viscosity of suspensions
Manuj Swaroop and John F. Brady
The bulk viscosity of a suspension is defined analogous to that for a pure fluid as the constant of proportionality relating the deviation of the trace of the macroscopic stress from its equilibrium value to the average rate of expansion. In a suspension the equilibrium macroscopic stress is the sum ... [J. Rheol. 51, 409 (2007)] published Tue May 1, 2007.
Direct Observation of a Transition of a Surface Plasmon Resonance from a Photonic Crystal Effect
Weili Zhang, Abul K. Azad, Jiaguang Han, Jingzhou Xu, Jian Chen et al.
Transition of surface-plasmon resonance from out-of-plane photonic crystal effect is observed in a semiconductor array of subwavelength holes by optical pump-terahertz probe measurements. The dielectric properties of the photoexcited array are essentially altered by the intense optical excitation du ... [Phys. Rev. Lett. 98, 183901 (2007)] published Tue May 1, 2007.
Resonant inelastic soft x-ray scattering, x-ray absorption spectroscopy, and density functional theory calculations of the electronic bulk band structure of CdS
L. Weinhardt, O. Fuchs, E. Umbach, C. Heske, A. Fleszar et al.
The electronic bulk band structure of CdS was studied by resonant inelastic soft x-ray scattering and x-ray absorption spectroscopy. The measurements at the S L-edge are compared with theoretical spectra calculated with the Kramers-Heisenberg formalism and density functional theory. The experimental ... [Phys. Rev. B 75, 165207 (2007)] published Mon Apr 30, 2007.
Dimensionality-dependent energy transfer in polymer-intercalated SnS[sub 2] nanocomposites
P. Parkinson, E. Aharon, M. H. Chang, C. Dosche, G. L. Frey et al.
We have investigated the influence of dimensionality on the excitation-transfer dynamics in a conjugated polymer blend. Using time-resolved photoluminescence spectroscopy, we have measured the transfer transients for both a three-dimensional blend film and for quasi-two-dimensional monolayers formed ... [Phys. Rev. B 75, 165206 (2007)] published Mon Apr 30, 2007.
Structural and electronic properties of the fullerene isomers of Si[sub 38]: A systematic theoretical study
Zacharias G. Fthenakis, Remco W. A. Havenith, Madhu Menon, and Patrick W. Fowler
A systematic study of the structural and electronic properties of the 17 Si[sub 38] fullerene cage isomers, which are constructed by making all possible permutations among their pentagons and hexagons, is presented. For the full optimization of these structures, a tight-binding molecular-dynamics me ... [Phys. Rev. B 75, 155435 (2007)] published Mon Apr 30, 2007.
Three-dimensional photonic crystal by holographic contact lithography using a single diffraction mask
Guangya Zhou and Fook Siong Chau
The authors present an approach for fabrication of three-dimensional (3D) periodic micro-nanoscale structures through holographic contact lithography using a single diffraction mask. The mask functions to split an incoming laser beam into four diffracted beams in an umbrella configuration to produce ... [Appl. Phys. Lett. 90, 181106 (2007)] published Mon Apr 30, 2007.
Role of the Si excess on the excitation of Er doped SiO[sub x]
Giorgia Franzo, Emanuele Pecora, Francesco Priolo, and Fabio Iacona
The authors have investigated the role of the Si excess on the photoluminescence properties of Er doped substoichiometric SiO[sub x] layers. They demonstrate that the Si excess has two competing roles: when agglomerated to form Si nanoclusters (Si-nc's) it enhances the Er excitation efficiency but i ... [Appl. Phys. Lett. 90, 183102 (2007)] published Mon Apr 30, 2007.
Shear strain in a shear band of a bulk-metallic glass in compression
W. H. Jiang, F. X. Liu, P. K. Liaw, and H. Choo
Using an infrared camera, the authors observe in situ the dynamic shear-banding operations in the geometrically constrained specimens of a bulk-metallic glass during compression at various strain rates. Based on the observed number of shear bands in a collection of simultaneous shear-banding operati ... [Appl. Phys. Lett. 90, 181903 (2007)] published Mon Apr 30, 2007.
Simple designs to avoid high-voltage discharge in a silicon electron beam-heating cell
Wang Ke-Fan, Shen Zhong-Lan, Xu Peng-Shou, Pan Hai-Bin, Zou Chong-Wen et al.
... [J. Vac. Sci. Technol. A 25, 629 (2007)] published Mon Apr 30, 2007.
Stress dependence of the polarized Raman spectrum of polycrystalline lead zirconate titanate
Marco Deluca, Tatsuo Sakashita, Wenliang Zhu, Hirokazu Chazono, and Giuseppe Pezzotti
The stress dependence of the Raman spectrum of a relaxor-based polycrystalline ferroelectric lead zirconate titanatelead nickel niobatelead zinc niobate (PZTPNNPZN) has been investigated using polarized Raman microprobe spectroscopy. Emphasis has been placed on explicitly working out the second harm ... [J. Appl. Phys. 101, 083526 (2007)] published Mon Apr 30, 2007.
Thermal effects on the electrical properties of (methyl orange)/ (polyvinyl alcohol) composites
Helinando P. de Oliveira and Celso P. de Melo
We have used electrical impedance spectroscopy to determine the dielectric characteristics of polymeric films prepared by incorporating varying amounts of methyl orange (MO), an azobenzene dye, into solid films of polyvinyl alcohol (PVA), an insulating polymer. By mapping the variation of relevant p ... [J. Appl. Phys. 101, 084113 (2007)] published Mon Apr 30, 2007.
Identification of nanoindentation-induced phase changes in silicon by in situ electrical characterization
S. Ruffell, J. E. Bradby, N. Fujisawa, and J. S. Williams
In situ electrical measurements during nanoindentation of Czochralski grown p-type crystalline silicon (100) have been performed using a conducting diamond Berkovich indenter tip. Through-tip current monitoring with a sensitivity of ~10 pA and extraction of current-voltage curves at various points ... [J. Appl. Phys. 101, 083531 (2007)] published Mon Apr 30, 2007.
Grain size effect on the dielectric behavior of nanostructured Ni[sub 0.5]Zn[sub 0.5]Fe[sub 2]O[sub 4]
N. Sivakumar, A. Narayanasamy, N. Ponpandian, and G. Govindaraj
The dielectric properties of nanocrystalline Ni[sub 0.5]Zn[sub 0.5]Fe[sub 2]O[sub 4] spinel ferrite with various grain sizes, obtained by mechanically milling, have been studied using impedance measurements in the frequency range from 1 Hz to 10 MHz and in the temperature range from 300 to 823 K. Th ... [J. Appl. Phys. 101, 084116 (2007)] published Mon Apr 30, 2007.
The paraelectric state in thin-film (Ba,Sr)TiO[sub 3]
M. Tyunina and J. Levoska
Vertical capacitor heterostructures of (Ba,Sr)TiO[sub 3] thin films with different Ba:Sr ratios, microstructures, and thicknesses were grown by in situ pulsed laser deposition using MgO or Al[sub 2]O[sub 3] substrates and La[sub 0.5]Sr[sub 0.5]CoO[sub 3] or Pt electrodes. The low-frequency dielectri ... [J. Appl. Phys. 101, 084119 (2007)] published Mon Apr 30, 2007.
Enhanced Raman scattering in thermally poled sodium-niobium borophosphate glasses
Marc Dussauze, Evelyne Fargin, Vincent Rodriguez, Artem Malakho, and Efstratios Kamitsos
Micro-Raman analysis has been carried out on the cross section of thermally poled sodium-niobium borophosphate glasses. We were able to measure with accuracy an enhanced Raman response from the nonlinear optical (NLO) layer formed at the anode side of the poled glasses. The thickness of the NLO laye ... [J. Appl. Phys. 101, 083532 (2007)] published Mon Apr 30, 2007.
Magnetophotorefractive effect of holographic recording in LiNbO[sub 3]:Fe crystals
Jiwei Qi, Jingjun Xu, Yudong Li, Fanlei Kong, Qian Sun et al.
An experimental investigation of the magnetophotorefractive effect for different holographic recording configurations is presented. Our results show that the diffraction efficiency of holographic grating strongly depends on the applied magnetic field for each configuration, since the magnetophotoref ... [J. Appl. Phys. 101, 083116 (2007)] published Mon Apr 30, 2007.
A ferromagnetic ferroelectric cofired ceramic for hyperfrequency
Yang Bai, Ji Zhou, Zhilun Gui, Longtu Li, and Lijie Qiao
A series of composite materials were prepared by cofired ceramics technology with 0.8Pb(Ni[sub 1/3]Nb[sub 2/3])O[sub 3]0.2PbTiO[sub 3] (PNNT) and Ba[sub 2]Zn[sub 1.2]Cu[sub 0.8]Fe[sub 12]O[sub 22] as two components. The weight fraction of PNNT, signed as x, varied from 0.1 to 0.9. The coexistence of ... [J. Appl. Phys. 101, 083907 (2007)] published Mon Apr 30, 2007.
Molecular simulation with variable protonation states at constant pH
Harry A. Stern
A new method is presented for performing molecular simulations at constant pH. The method is a Monte Carlo procedure where trial moves consist of relatively short molecular dynamics trajectories, using a time-dependent potential energy that interpolates between the old and new protonation states. Co ... [J. Chem. Phys. 126, 164112 (2007)] published Mon Apr 30, 2007.
Two-phase structure of polyelectrolyte gel/surfactant complexes
Denis Tararyshkin, Elena Kramarenko, and Alexei Khokhlov
The behavior of lightly cross-linked polyelectrolyte hydrogel swelling in the solution of oppositely charged surfactants is studied theoretically. It is shown that if there is a lack of surfactant in the solution intragel separation into two phases differing in swelling ratios and surfactant content ... [J. Chem. Phys. 126, 164905 (2007)] published Mon Apr 30, 2007.
Two-phase structure of polyelectrolyte gel/surfactant complexes
Denis Tararyshkin, Elena Kramarenko, and Alexei Khokhlov
The behavior of lightly cross-linked polyelectrolyte hydrogel swelling in the solution of oppositely charged surfactants is studied theoretically. It is shown that if there is a lack of surfactant in the solution intragel separation into two phases differing in swelling ratios and surfactant content ... [J. Chem. Phys. 126, 164905 (2007)] published Mon Apr 30, 2007.
Molecular simulation with variable protonation states at constant pH
Harry A. Stern
A new method is presented for performing molecular simulations at constant pH. The method is a Monte Carlo procedure where trial moves consist of relatively short molecular dynamics trajectories, using a time-dependent potential energy that interpolates between the old and new protonation states. Co ... [J. Chem. Phys. 126, 164112 (2007)] published Mon Apr 30, 2007.
Swinging of Red Blood Cells under Shear Flow
Manouk Abkarian, Magalie Faivre, and Annie Viallat
We reveal that under moderate shear stress (etagamma-dot [approximate]0.1 Pa) red blood cells present an oscillation of their inclination (swinging) superimposed to the long-observed steady tank treading (TT) motion. A model based on a fluid ellipsoid surrounded by a viscoelastic membrane initially ... [Phys. Rev. Lett. 98, 188302 (2007)] published Mon Apr 30, 2007.
Transition-metal silicides as materials for magnet-semiconductor heterostructures
Peter Kratzer, S. Javad Hashemifar, Hua Wu, Mahbube Hortamani, and Matthias Scheffler
The injection of a spin-polarized current into a semiconductor, one of the key requirements for spintronics, poses the challenge for computational materials science to possibly screen suitable materials. In a number of theoretical investigations, we have put forward magnetic intermetallic compounds ... [J. Appl. Phys. 101, 081725 (2007)] published Fri Apr 27, 2007.
Dynamics of DNA tumbling in shear to rotational mixed flows: Pathways and periods
Joo Sung Lee, Eric S. G. Shaqfeh, and Susan J. Muller
The tumbling dynamics of DNA have been examined via experiments and Brownian dynamics (BD) simulations in mixed flows that vary from pure shear to pure rotation. In shear, tumbling pathways and periods agree well with earlier studies; in rotation-dominated flows, a new tumbling pathway is identified ... [Phys. Rev. E 75, 040802 (2007)] published Fri Apr 27, 2007.
Large-scale correlated calculations of linear optical absorption and low-lying excited states of polyacenes: Pariser-Parr-Pople Hamiltonian
Priya Sony and Alok Shukla
We present large-scale correlated calculations of the linear optical absorption spectrum of oligo-acenes containing up to seven benzene rings. For the calculations we used the Pariser-Parr-Pople (PPP) Hamiltonian, along with the configuration interaction (CI) technique at various levels such as the ... [Phys. Rev. B 75, 155208 (2007)] published Fri Apr 27, 2007.
Dynamics of charge transfer: Rate processes formulated with nonequilibrium Green's functions
Sina Yeganeh, Mark A. Ratner, and Vladimiro Mujica
The authors examine the connection between electron transport under bias in a junction and nonadiabatic intramolecular electron transfer (ET). It is shown that under certain assumptions it is possible to define a stationary current that allows the computation of the intramolecular transfer rate usin ... [J. Chem. Phys. 126, 161103 (2007)] published Fri Apr 27, 2007.
Optimization of the incident angle in infrared spectroscopic ellipsometry: Spectra of C[sub 18]-alkylthiol monolayers
Z. G. Hu and P. Hess
A detailed analysis of the features of C[sub 18]-alkylthiol/gold (silver) spectra is presented to interpret the results obtained by infrared spectroscopic ellipsometry (IRSE). The interactions between neighboring vibrational bands, the effect of different incident angles, and the Berreman effect are ... [J. Vac. Sci. Technol. A 25, 601 (2007)] published Fri Apr 27, 2007.
Nanocrystal indium doped zinc oxide prepared by spray pyrolysis method
A. Tanuševski, M. Ristova, M. Ristov, and V. Georgieva
Thin films of indium-doped zinc oxide have been prepared by spray pyrolysis of the methanol solution of zinc acetate on heated substrates. As prepared films show hexagonal wurtzite nanocrystal structure. The films have 90 % transmission for wavelength more than 550 nm, but the conductivity depends f ... [AIP Conf. Proc. 899, 801 (2007)] published Fri Apr 27, 2007.
Microscopical Examination of Ancient Silver Coins
N. Pistofidis, G. Vourlias, El. Pavlidou, T. Dilo, N. Civici et al.
The microstructure of three silver coins of the III[sup d] century B.C. from the Illyrian king Monounios, the ancient Greek city of Dyrrachion and of Korkyra was studied with XRF and microscopy. From this investigation it turned out that these coins have different chemical composition and microstruc ... [AIP Conf. Proc. 899, 798 (2007)] published Fri Apr 27, 2007.
Ethylene-Propylene Terpolymer Rubber Processing by Electron Beam Irradiation
Elena N. Manaila, Maria Daniela T. Zuga, Diana I. Martin, Gabriela D. Craciun, Daniel I. Ighigeanu et al.
The investigations on the cross-linking by accelerated electrons of 6.23 MeV in lowly unsaturated elastomers of EPDM (ethylene-propylene terpolymer rubber) type are presented. Two rubber blends based EPDM were prepared and irradiated at different doses up to 250kGy: blend A based on EPDM maleinized ... [AIP Conf. Proc. 899, 785 (2007)] published Fri Apr 27, 2007.
Study of Anodic Oxide Films on Silicon Carbide
Stanislav Lilov
Anodic oxide films were grown on SiC using various electrolytes. The obtained oxide films were compared and some of their electrophysical properties were investigated. Anodic oxidation of SiC was shown to be useful for precise removal of layers as well as for identification of the polar faces of SiC ... [AIP Conf. Proc. 899, 784 (2007)] published Fri Apr 27, 2007.
Non-reproducible Electrical Properties Of Semiconductor PVDF-HFP (Hexafluoropropylenevinylidenefluoride) Copolymer
Gulbeden Likoglu, H. Yuksel Guney, and Ufuk Abaci
The I-V characteristic of carbon black-filled PVDF-HFP copolymer has been investigated as functions of electrical field, temperature and time. In addition, the conductivity has been measured by applying fixed voltage at different temperature. Electrical properties of the carbon-black-filled PVDf-HFP ... [AIP Conf. Proc. 899, 783 (2007)] published Fri Apr 27, 2007.
Crystal Structure and Magnetic Properties of YNi[sub 5 - x]Al[sub x] Compounds
C. Lazar and E. Burzo
The YNi[sub 5x]Al[sub x] compounds crystallize in a hexagonal structure of CaCu[sub 5]-type for x <= 1.5. The magnetic susceptibility of YNi[sub 5] at T < 10 K follows a T[sup 2] dependence. At T > T*, a Curie-Weiss behaviour was shown. Similar dependencies were observed in all studied composition r ... [AIP Conf. Proc. 899, 782 (2007)] published Fri Apr 27, 2007.
Application of Electron Beams, Microwaves and Catalysis to Volatile Organic Compounds Decomposition
Daniel I. Ighigeanu, Ioan I. Calinescu, Diana I. Martin, and Constantin I. Matei
A hybrid technique, developed for volatile organic compounds (VOCs) decomposition using electron beam (EB) irradiation, microwave (MW) treatment, and catalyst method, is presented. The combination of a non-thermal plasma (NTP) induced by both, EB and MW, with in situ heterogeneous catalysis (denoted ... [AIP Conf. Proc. 899, 780 (2007)] published Fri Apr 27, 2007.
Electromechanical Response of Polyurethane Films With Different Thicknesses
I. Diaconu, Dana-Ortansa Dorohoi, Liana-Catalina Ciobanu, and C. Ciobanu
In this paper the static electric field induced strain, dielectric and mechanical properties of polyurethane elastomer films with different thicknesses were investigated. (C)2007 American Institute of Physics ... [AIP Conf. Proc. 899, 774 (2007)] published Fri Apr 27, 2007.
Magnetic and Electronic Properties of R[sub 3]Ni[sub 7]B[sub 2] Compounds where R = Dy, Ho, Er
N. Bucur, P. Vlaic, and E. Burzo
Band structure calculations show the presence of small magnetic moments at Ni sites. Magnetic measurements at 4.2 K evidenced a relative high anisotropy. Magnetic behavior of nickel is analyzed in spin fluctuation model. (C)2007 American Institute of Physics ... [AIP Conf. Proc. 899, 766 (2007)] published Fri Apr 27, 2007.
Magnetic properties of Sr[sub 2]FeMo[sub 1 - x]M[sub x]O[sub 6] perovskites with M = W or Ta
I. Balasz, E. Burzo, and M. Valeanu
The Sr[sub 2]FeMo[sub 1x]M[sub x]O[sub 6] perovskites with M = W or Ta and x <= 0.3 were studied by x-ray and electron microscopy. The magnetic and magnetoresistive properties were correlated with their microstructures. The effect of sintering time on their physical properties was analysed. (C)2007 ... [AIP Conf. Proc. 899, 763 (2007)] published Fri Apr 27, 2007.
Studying On The Small Molecule Diffusion Into Hydrogels: A Fluorescence Study
G. A. Evingur, K. Karsli, and O. Pekcan
In situ steady state fluorescence experiments (SSF) were reported during the diffusion of water molecules into PAAm gels at various temperatures. The fluorescence emission intensities, I[sub p] increased continuously as water molecules diffused into gels. I[sub sc], scattered light intensities, from ... [AIP Conf. Proc. 899, 761 (2007)] published Fri Apr 27, 2007.
Some Properties of Zinc Oxide Thin Films Obtained by Cathodic Electrodeposition
V. Georgieva and A. Tanusevski
This paper explains some properties of wide-band gap zinc oxide (ZnO) thin films cathodic electrodeposited from an aqueous solution composed 0,1 M zinc nitrate at 65 degrees C. Transparent conducting optically glass coated with tin oxide (SnO[sub 2]) was used as cathode. Preparing of the ZnO films, ... [AIP Conf. Proc. 899, 756 (2007)] published Fri Apr 27, 2007.
Photoinduced Dichroism In Polymer Films Sensitized With Stilbene-type Molecules
Detelina Ilieva, Tsveta Petrova, and Violeta Dragostinova
We report a spectrophotometric investigation of the photoprocesses in different polymer films containing stilbene and stilbenecarboxaldehyde. We have observed considerable photoinduced changes in the absorption spectra of the samples due to trans-cis photoisomerization of the stilbene-type molecules ... [AIP Conf. Proc. 899, 681 (2007)] published Fri Apr 27, 2007.
Corona Charged Polypropylene Films Irradiated by CO[sub 2] and CuBr Vapor Lasers
T. A. Yovcheva, T. A. Eftimov, A. P. Viraneva, G. A. Mekishev, V. C. Yanev et al.
The influence of CuBr vapor (Cu-Br) and CO[sub 2] laser radiation on polypropylene corona electrets is investigated in the present paper. The surface potential was measured before (V[sub 0]) and after (V[sub irr]) irradiation using the method of the vibrating electrode with compensation. The sample ... [AIP Conf. Proc. 899, 673 (2007)] published Fri Apr 27, 2007.
X-ray and Dielectric Spectroscopy Studies Of Chiral Ferroelectric Liquid Crystals With Keto Group
Maja Stojanović, Dusanka Ž. Obadović, Alexej Bubnov, Vera Hamplova, and Miroslav Kaspar
Series of ferroelectric liquid crystals with the keto group attached to the molecule core and one lactate group as the chiral centre have been studied by X-ray and dielectric spectroscopy. The thickness of smectic layers and the average distance between the long axes of neighboring molecules increas ... [AIP Conf. Proc. 899, 659 (2007)] published Fri Apr 27, 2007.
Structural, Electronic and Dynamical Properties of GeSi: An Ab-initio Study
F. Soyalp, S. Ugur, and G. Ugur
A theoretical study of electronic and dynamical properties of GeSi is presented using the ab-initio pseudopotential method and a linear response scheme, within the local density approximation. The calculated values for the lattice constant, bulk modulus and its first derivative are in agreement with ... [AIP Conf. Proc. 899, 655 (2007)] published Fri Apr 27, 2007.
Dielectric Properties of Iron- and Sodium-Fumarate
Sonja J. Skuban, Tanja Džomić, and Agneš Kapor
The behaviour of dielectric parameters such as relative dielectric constant (epsilon[prime]), relative loss factor (epsilon[double-prime]) and ac conductivity of well known pharmaceutical materials Fe(II)-fumarate and sodium-fumarate have been studied as a function of temperature (range 303 K to 483 ... [AIP Conf. Proc. 899, 652 (2007)] published Fri Apr 27, 2007.
Effect of Substrate Temperature on The Structural and Optical Properties of Non-doped ZnO Thin Films
Saliha Ilican, Mujdat Caglar, and Yasemin Caglar
Transparent conducting non-doped zinc oxide (ZnO) thin films have been deposited by the spray pyrolysis method at different substrate temperatures. X-ray diffraction spectra of the films have shown that the films are polycrystalline and hexagonal wurtzite in structure. From these spectra, grain size ... [AIP Conf. Proc. 899, 651 (2007)] published Fri Apr 27, 2007.
A Comparative Study of Electrical Resistivity of Liquid Alkaline Earth Metals
S. D. Korkmaz, S. Korkmaz, and F. Resuloglu
The resistivities of liquid alkaline earth metals are investigated using Ziman formula and the alternative expression based on Kubo formula suggested by Unal and Alkan [J. Phys. Soc. Jpn. 62 (1993) 2425]. As the input pseudopotential the individual version of the electron-ion potential proposed by F ... [AIP Conf. Proc. 899, 649 (2007)] published Fri Apr 27, 2007.
Characterization of Mechanically Activated ZnO Powders by Raman, Luminescence and IR Spectroscopy
M. J. Šćepanović, Z. D. Dohčević-Mitrović, T. Srećković, K. Vojisavljević, and Z. V. Popović
Commercial zinc oxide powder was mechanically treated by grinding in a high-energy vibro-mill in a continual regime in air up to 300 minutes. Original and modified ZnO samples were characterized by Raman, photoluminescence (PL) and infrared (IR) spectroscopy. This study confirms that change in defec ... [AIP Conf. Proc. 899, 648 (2007)] published Fri Apr 27, 2007.
Development of Space Instabilities of Defect Distribution at High Fluences in Neutron Irradiated YBa[sub 2]Cu[sub 3]O[sub 7 - delta ] Ceramics
V. Sandu, S. Popa, E. Sandu, D. Di Gioacchino, and P. Tripodi
We investigated the behaviour of YBa[sub 2]Cu[sub 2]O[sub 7delta] ceramics by multiharmonic ac-susceptibility. We have found an unexpected improvement of the intragranular response at the highest fluence 9.98 10[sup 17] neutrons/cm[sup 2]. However, this fact is accompanied with a continuous suppress ... [AIP Conf. Proc. 899, 647 (2007)] published Fri Apr 27, 2007.
Electrodeposited NiCo/Cu Superlattices
M. Safak and M. Alper
NiCo/Cu superlattices were electrodeposited on polycrystalline Cu substrates from a single electrolyte under potentiostatic control. The X-ray diffraction (XRD) patterns showed that NiCo/Cu superlattices have the same crystal structure and texture as in their substrates. The films exhibited giant ma ... [AIP Conf. Proc. 899, 644 (2007)] published Fri Apr 27, 2007.
Effects of post-deposition heat treatment on the optical characteristics of ZnTe thin films
P. Prepelita, C. Pirghie, and G. I. Rusu
Zinc telluride (ZnTe) thin films (d=0.15 [mu]m 2.40 [mu]m) were deposited by quasi-closed volume technique under vacuum. X-ray diffraction patterns indicated that the films are polycrystalline and have a zinc blende structure. After a heat treatment, a significant increase of peak intensities, corr ... [AIP Conf. Proc. 899, 641 (2007)] published Fri Apr 27, 2007.
Spectroscopic Studies On Powdered CeNi[sub 5] Oxidized In Air
M. Coldea, R. Pacurariu, M. Neumann, L. G. Pascut, and V. Rednic
The synthesis, X-ray photoelectron spectroscopy (XPS), Raman spectroscopy. X-ray diffraction (XRD) and transmission electron microscopy (TEM) of Ni isolated single domain particles, obtained from powdered CeNi[sub 5] oxidized in air at different temperatures up to 800 degrees C, are reported. (C)200 ... [AIP Conf. Proc. 899, 636 (2007)] published Fri Apr 27, 2007.
Energies of Electronic States of Ni (II) Ion in NiO-Al[sub 2]O[sub 3] Catalyst Prepared by Impregnation
D. Ž. Obadović, J. Kiurski, and R. P. Marinković-Nedučin
The behavior of NiO-Al[sub 2]O[sub 3] catalysts is strongly dependent on the preparation method, as well as on pretreatment conditions. In the present work we investigated the influences of Ni(II) ion on NiO-Al[sub 2]O[sub 3] catalysts properties due to the preparation by impregnation method. Based ... [AIP Conf. Proc. 899, 634 (2007)] published Fri Apr 27, 2007.
Simulation of the Interfacial AlN Layer on Band Structures and Carrier Densities of AlGaN/GaN HEMT Structures
S. B. Lisesivdin and M. Kasap
At high electron mobility transistors (HEMT), increase of 2DEG carrier density is an important issue to achieve high performance. Inserting a thin undoped AlN interfacial layer between undoped AlGaN barrier and undoped GaN channel layer is one of the methods to achieve high performance AlGaN/GaN HEM ... [AIP Conf. Proc. 899, 622 (2007)] published Fri Apr 27, 2007.
Thermodynamic Analysis of the High Temperature Processes in the System Si-C-H-Cl
Stanislav Lilov
In the present work a thermodynamic analysis of the interaction processes in the Si-C-H-Cl system in the temperature interval 10003000 K is carried out. The optimal conditions giving the maximum yield of the silicon carbide by pyrolysis of mixture of volatile compounds of carbon and silicon have bee ... [AIP Conf. Proc. 899, 621 (2007)] published Fri Apr 27, 2007.
Epitaxial Growth Of Y[sub 2]O[sub 3] On Biaxially Textured Ni Tapes Using A Sol-Gel Process For YBCO Coated Conductors
L. Ciontea, T. Ristoiu, R.-C. Suciu, and T. Petrisor
A solution processing technique was used to deposit an epitaxial Y[sub 2]O[sub 3] film on (001)[100] cube textured Ni tapes for YBa[sub 2]Cu[sub 3]O[sub x] (YBCO) coated conductors manufacturing. The cube texture was developed in Ni by a conventional thermo-mechanical process. A precursor solution o ... [AIP Conf. Proc. 899, 620 (2007)] published Fri Apr 27, 2007.
Growth, Optical and Electirical Properties of In[sub 2]S[sub 3], In[sub 1 - x]Cd[sub x]S and CdS Thin Films by the (SILAR) Method
M. Kundakci, Y. Akaltun, A. Astam, A. Ates, M. Yildirim et al.
In[sub 2]S[sub 3] and In[sub 1x]Cd[sub x]S and CdS thin films were grown on glass substrates by using Successive Ionic Layer Adsorption and Reaction (SILAR) technique at room temperature. The band gap energies of the films were determined by optical absorption measurements. The optical absorption me ... [AIP Conf. Proc. 899, 618 (2007)] published Fri Apr 27, 2007.
TEM Study of Compositional Modulations in a GaInAsSb Film Grown on GaSb Vicinal Substrates
S. Konidaris, P. Szczeszek, E. K. Polychroniadis, and F. Dimroth
Quaternary semiconductor alloys based on GaSb are suitable for thermophotovoltaic (TPV) cell applications as they have low and adjustable band-gap. However, they exhibit phase separation which destroys band-gap uniformity. In this work, GaInAsSb thin films grown on GaSb vicinal substrates with diffe ... [AIP Conf. Proc. 899, 615 (2007)] published Fri Apr 27, 2007.
Correlation Between Dielectric Properties And Crystal Structure Of Sodium Maleate
Agneš Kapor, Sonja Skuban, and Tanja Džomić
The behavior of dielectric parameters: such as permittivity (epsilon[prime]), loss factor (epsilon[double-prime]), loss tangent (tan delta) and ac conductivity has been studied as a function of frequency (range 0.1 Hz to 100 kHz). The analysis of the variation of epsilon[double-prime] with frequency ... [AIP Conf. Proc. 899, 612 (2007)] published Fri Apr 27, 2007.
Dielectric Properties Of Nanoferrites
Stevan B. Jankov, Zeljka N. Cvejic, Srdjan Rakic, and Vladimir Srdic
Dielectric properties: permittivity, loss factor, tan delta and ionic conductivity of nanostructured ferrites have been measured. Samples used were nickel, zinc and yttrium doped ferrites mixed in various ratios. The synthesis has been performed using precipitation method and obtained powders were p ... [AIP Conf. Proc. 899, 609 (2007)] published Fri Apr 27, 2007.
Band Gap Energies of CdO:F Semiconductor Films Produced by Ultrasonic Spray Pyrolysis Method
Sinan Irmak and Metin Kul
The fluorine doped cadmium oxide (CdO:F) samples have been deposited by ultrasonic spray pyrolysis method (USP). The absorption spectra of the samples showed that CdO:F is a direct band gap material. The direct optical transition has shifted towards the shorter wavelengths, and the transparency of t ... [AIP Conf. Proc. 899, 608 (2007)] published Fri Apr 27, 2007.
Crystallization Behaviour of Amorphous Al-Ni-Nd Alloy
Musa Gogebakan and Alaaddin Gundes
In this study, crystallization behaviour of rapidly solidified Al[sub 85]Ni[sub 5]Nd[sub 10] alloy has been investigated by differential scanning calorimetry (DSC). Continuous heating DSC trace of amorphous Al[sub 85]Ni[sub 5]Nd[sub 10] alloy consisted of three exothermic peaks. This indicated that; ... [AIP Conf. Proc. 899, 606 (2007)] published Fri Apr 27, 2007.
Thermal Properties of Amorphous Al-Ni-Si Alloy
Musa Gogebakan and Mustafa Okumus
Thermal properties of the amorphous phases in rapidly solidified Al[sub 70]Ni[sub 13]Si[sub 17] alloy has been investigated by a combination of differential scanning calorimetry DSC. During continuous heating, three exothermic crystallization peaks were observed. Activation energies for the three cr ... [AIP Conf. Proc. 899, 604 (2007)] published Fri Apr 27, 2007.
Formation and Microstructure of Quasicrystalline Al-Fe-Cu Alloy by Mechanical Alloy
Musa Gogebakan and Baris Avar
In the present investigation, we examined the i-phase formation during Mechanical Alloying (MA) of Al[sub 70]Cu[sub 20]Fe[sub 10] elemental blend using X-ray diffraction (XRD). (C)2007 American Institute of Physics ... [AIP Conf. Proc. 899, 603 (2007)] published Fri Apr 27, 2007.
Isotope Effect in Perovskite-Type Ferroelectrics
Bahattin Erdinc and Faruk Karadag
We discuss theoretically the isotope effects on phase transition temperature T[sub c] and generalized force constant k[sub f] in perovskite-type ferroelectric. We give the result of our calculation on the reduced force constant of the soft optic phonon with quantum-mechanical electron-phonon interac ... [AIP Conf. Proc. 899, 600 (2007)] published Fri Apr 27, 2007.
Cadmium Sulfide Thin Films Grown By Chemical Bath Deposition Method
S. Erat and H. Metin
CdS thin films were deposited by the chemical bath deposition (CBD) from a bath containing CdSO[sub 4], thiourea and ammonia. The effect of annealing in air on the optical properties of CdS thin films was investigated. The quality of CBD CdS thin films was analyzed at different condition of temperat ... [AIP Conf. Proc. 899, 599 (2007)] published Fri Apr 27, 2007.
Role of Local Density Approximation in structure and electronic properties of In[sub x]Ga[sub 1 - x]As alloys
A. Uzel, P. Durmus, M. Cakmak, and S. Ozcelik
The wurtzite In[sub x]Ga[sub 1x]As (x = 0.5) alloys are studied by numerical simulation based on first-principles calculations. The results indicate that the band gap bowing parameters obtained with the equilibrium lattice constant. As a precursor to obtaining the band offsets, the electronic band s ... [AIP Conf. Proc. 899, 595 (2007)] published Fri Apr 27, 2007.
Ab-Initio Total Energy Calculations on the AlBi Compound
E. Deligoz, K. Colakoglu, and Y. O. Ciftci
We present the results of the structural, thermodynamical, elastic, and electronic properties of the hypothetical aluminum bismuth (AlBi) compound (III-V) in zinc-blende phase by performing ab initio total energy calculations within the local density approximation in Siesta package. Particularly, we ... [AIP Conf. Proc. 899, 593 (2007)] published Fri Apr 27, 2007.
Frequency-dependent conductivity in unannealed thin films of As[sub 0.40]Se[sub 0.40]Te[sub 0.20]
Bukem Bilen, Yani Skarlatos, and Gulen Aktas
D.c. and a.c. conductivity measurements have been performed on unannealed amorphous As[sub 0.40]Se[sub 0.40]Te[sub 0.20] thin films. The d.c. behaviour of the samples indicates hopping conduction mechanisms between 143K210K and 210K343K. The a.c. conductivity of the films is well represented by the ... [AIP Conf. Proc. 899, 588 (2007)] published Fri Apr 27, 2007.
The Conductivity Properties of TlBi(Se[sub 1 - x]S[sub x])[sub 2]Crystals
S. Ballikaya and S. Yildirim
In the past forty years we witnessed a tremendous progress in technology. Use of semiconductors in electronic industry has played an extremely important role in this. The remarkable physical properties like high conductivity, thermo-electric power and photosensitivity of layered single crystals, suc ... [AIP Conf. Proc. 899, 585 (2007)] published Fri Apr 27, 2007.
Numerical Calculation Of The Hall Mobility Of InP
Senem Aydogu and Omer Ozbas
The aim of this work, the Hall mobility of InP semiconductor compound which is technologically important material is calculated with iterative method. Furthermore, it is investigated that the calculated values of mobility are depended on temperature interval 30 600K and carrier concentrations at 30 ... [AIP Conf. Proc. 899, 582 (2007)] published Fri Apr 27, 2007.
Electrical and Optical Characterization of Bis(7-methoxybenzofuran-2-il)ketone
F. Dagdelen, M. Koca, C. Kirilmis, and Y. Aydogdu
The electrical and optical properties of Bis(7-methoxybenzofuran-2-il)ketone have been experimentally characterized. The optical band gap of Bis(7-methoxybenzofuran-2-il)ketone was found as 2.76 eV. Single-oscillator energy and dispersion energy of the sample were calculated by plotting (n[sup 2]1)[ ... [AIP Conf. Proc. 899, 581 (2007)] published Fri Apr 27, 2007.
Growth, Optical and Electirical Properties of In[sub 2]Se[sub 3] Thin Films by the (SILAR) Method
A. Astam, M. Kundakci, Y. Akaltun, A. Yildirim, A. Ates et al.
Indium selenide (In[sub 2]Se[sub 3]) thin films were grown on glass substrates by using Successive Ionic Layer Adsorption and Reaction (SILAR) technique at room temperature. The In[sub 2]Se[sub 3] thin films have been characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) fo ... [AIP Conf. Proc. 899, 579 (2007)] published Fri Apr 27, 2007.
The Study of the Effect of Solvents Absorption in PET Packaging Films
Cenk Denktas and Huseyin Yildirim
The effects of absorption solvents into poly(ethylene terephtalete) (PET) films, which are used as food packaging materials, was investigated by DSC, SEM and mechanical methods at various temperatures (5, 25 and 40 degrees C) and for different periods (18 weeks), respectively. Due to the interactio ... [AIP Conf. Proc. 899, 560 (2007)] published Fri Apr 27, 2007.
The Preliminary Stretching Effect on Mechanical Properties of Natural and Synthetic Polyamide fibres and Conformational Transitions
Baki Aksakal, Svetlana P. Phoshkina, Diana M. Darvish, Ekaterina S. Tsobkallo, and Vilayet Alekberov
The preliminary stretching effect on mechanical properties of natural (wool, hair, and silk) and synthetic polyamide fibres (nylon, capron) and conformational transitions are investigated by using a tensile tester. It is shown that alpha-keratin fibres (wool and hair) show silk-like properties and p ... [AIP Conf. Proc. 899, 554 (2007)] published Fri Apr 27, 2007.
Age Hardening Kinetics in 7xxx Type (Al-Mg-Zn) Alloys
A. Vevecka-Priftaj, E. Lamani, J. Fjerdingen, Y. Langsrud, J. Gjonnes et al.
Age hardening in industrial 7xxx alloys at the temperature 100 degrees and 150 degrees C up to 144 hrs, after solid solution treatments at 450 degrees and 550 degrees C, has been followed by measurements of Vickers hardness, scanning and transmission electron microscopy. The influence of silicon o ... [AIP Conf. Proc. 899, 461 (2007)] published Fri Apr 27, 2007.
An Experimental Work On The Electrical Conductivity Of PEG Under Changing Relative Humidity
O. Erdamar, Y. Skarlatos, G. Aktas, and M. N. Inci
Polyethylene glycol (PEG) thin films are investigated experimentally. Dc measurements are done under changing relative humidity (rh) to study the change in the electrical conductivity. Upto 70 % rh, electronic conduction takes place with the increase in the current as a result of the absorbed water. ... [AIP Conf. Proc. 899, 441 (2007)] published Fri Apr 27, 2007.
The Determination of Birefringence Dispersion in Nematic Liquid Crystals by Using the S-Transform
E. Coskun, S. Ozder, O. Kocahan, and O. Koysal
Transmittance spectra of 5CB and ZLI-6000 coded nematic liquid crystals were acquired in the 1260022200 cm[sup 1] region at room temperature. The S-transform was applied to analyze the transmittance signal. Dispersion curves of the birefringence were obtained for 5CB and ZLI-6000 by this analysis an ... [AIP Conf. Proc. 899, 439 (2007)] published Fri Apr 27, 2007.
Electrical Properties of High Temperature Insulation Coatings under various Pressures at 298 K and 77 K
O. Cakiroglu and L. Arda
The high temperature insulation coatings were prepared using solution of Mg and Zr based precursors. Then the MgO-ZrO[sub 2] coating was applied on long-length Stainless-Steel tapes using a non-vacuum reel-to-reel sol-gel dip coating technique. The thicknesses of coatings 7, 12 and 15 [mu]m for 4, 8 ... [AIP Conf. Proc. 899, 431 (2007)] published Fri Apr 27, 2007.
The Simulation of the Modes in a Photonic Crystal Bend Waveguide for Two Different Compositions
Halime Demir and Sedat Ozsoy
In this study, we investigated the behavior of the TE mode fields in a photonic crystal bend waveguide, for different lattice constants and radii of dielectric rods in the visible and infrared regions. Results are obtained by using FEMLAB simulation software for two different compositions and discus ... [AIP Conf. Proc. 899, 315 (2007)] published Fri Apr 27, 2007.
Electrical and Optical Properties of ZnO-Fe[sub 2]O[sub 3]-SiO[sub 2] Composite Prepared by SOL-GEL Method
C. Aksu Canbay, S. Altin, A. Aydogdu, Y. Aydogdu, and E. Yakinci
The semiconductor composite was prepared from ZnO, Fe[sub 2]O[sub 3] and SiO[sub 2] transition metal oxides by sol-gel method. The surface morphology of the prepared samples were investigated by scanning electron microscopy (SEM). The activation energies of the samples in the extrinsic and intrinsic ... [AIP Conf. Proc. 899, 297 (2007)] published Fri Apr 27, 2007.
Analysis of Ternary InGaN Layers Grown By Atmospheric Pressure Vertical MOVPE
A. Yildiz, M. K. Ozturk, and M. Kasap
We present a study on the n-type ternary InGaN layers grown by atmospheric pressure vertical metal organic chemical vapor deposition on GaN template/(0001) sapphire substrate. An investigation in the different growth conditions on n-type of the In[sub x]Ga[sub 1x]N, alloys was made for three series ... [AIP Conf. Proc. 899, 295 (2007)] published Fri Apr 27, 2007.
Structural, Optical and Electrical Properties of Sol-Gel Derived Titanium Dioxide Thin Film
Dilek Taskin, Fatih Dumludag, and Ahmet Altindal
Optical, structural and electrical (dc and ac) properties of sol-gel derived TiO[sub 2] film in a wide range of temperature (290 652 K) were investigated. XRD analysis was used for investigation the crystallinity of the films. Optical bad gap of the film were determined from transmission spectra. W ... [AIP Conf. Proc. 899, 285 (2007)] published Fri Apr 27, 2007.
Study of Degradation Processes in Dielectric Materials Used in Electronic Control Equipment Operated in ``Kozloduy'' NPP
Nayden Naydenov and Angel Popov
The electronic equipment for control of different systems of Units 5 and 6 is studied for presence of degradation processes occurring in result of continuous usage in conditions of controlled radiation background in compliance with Kozloduy NPP safety codes. Systems, operated in a continuous mode in ... [AIP Conf. Proc. 899, 275 (2007)] published Fri Apr 27, 2007.
Structural and Optical Properties of Cadmium Selenide Films Prepared by Chemical Bath Deposition
S. Erat and H. Metin
Cadmium selenide (CdSe) thin films were deposited by a simple and inexpensive chemical bath deposition (CBD). The films were deposited using cadmium nitrate as a Cd[sup 2+] ion source and sodium selenosulfate as a Se[sup 2] ion source. The films were characterized by using X-ray diffraction, optical ... [AIP Conf. Proc. 899, 249 (2007)] published Fri Apr 27, 2007.
Modifications in the Band Structure of a 2-Dimensional Kerr-Nonlinear Photonic Crystals
Ahmet Cicek and Bulent Ulug
Modifications in the band structure of a 2-dimensional photonic crystal composed of a square array of circular air holes drilled in a Kerr-type nonlinear dielectric material are investigated. Special attention is paid on the position and width of the overlap region of TE and TM band gaps. Angular fr ... [AIP Conf. Proc. 899, 241 (2007)] published Fri Apr 27, 2007.
Induced transition metal moments in rare-earth (yttrium) compounds
E. Burzo
The exchange interactions were analysed in rare-earth (yttrium) transition metal compounds. A transition from nonmagnetic to magnetic state was shown for Co and Ni at ~= 70 T and ~= 35 T, respectively. The temperature dependences of the magnetic susceptibilities, for the exchange enhanced paramagnet ... [AIP Conf. Proc. 899, 239 (2007)] published Fri Apr 27, 2007.
The Effect of Ambient Conditions on the Impedance Spectra of Newly Synthezised Organic Semiconductor Thin Films
Yasemin Aktas, Pinar Sen, Fatih Dumludag, Ahmet Altindal, Metin Ozer et al.
A detailed study of the effect of the film preparation conditions on the d.c conductivity and impedance spectra of a newly synthesized trinuclear phthalocyanine (ZnPc) derivative were carried out at the temperatures between 290 K and 420 K. We find that the experimental data are described by thermal ... [AIP Conf. Proc. 899, 233 (2007)] published Fri Apr 27, 2007.
Investigation of Structural and Optical Properties of InP Thin Films Developed by Using Spraying Method
Funda Aksoy, Refik Kayali, Mustafa Oztas, and Metin Bedir
Structural and optical properties of InP films developed with the solutions prepared with InCl[sub 3] and Cl[sub 2]HPO[sub 4] salts having different rates by using spraying method have been investigated using the data obtained from UV spectrometer and XRD (x-ray difractometer). Band gap energy value ... [AIP Conf. Proc. 899, 231 (2007)] published Fri Apr 27, 2007.
Synthesis and Effects of Substrate Temperature on ac and dc Electrical Properties of Cobalt Phthalocyanine (CoPc) Thin Films
Fatma Nur Aki, Dilek Dogan, Fatih Dumludag, Ahmet Altindal, Mustafa Bulut et al.
In this study, 4,4[prime],4[double-prime]-[benzene-1,3,5-tryltris(oxy)]tri-9,10,16,17,23,24-hexa(hexylthio)phthalocyaninatocobalt(II) has been synthesized from 4-[3,5-bis(3,4-dicyanophenoxy)phenoxy]phthalonitrile and 4,5-bishexylthiophthalonitrile with CoCl[sub 2]6H[sub 2]O in ethylene glycol at 170 ... [AIP Conf. Proc. 899, 229 (2007)] published Fri Apr 27, 2007.
Large-scale simulations of complex physical systems
A. Belić
Scientific computing has become a tool as vital as experimentation and theory for dealing with scientific challenges of the twenty-first century. Large scale simulations and modelling serve as heuristic tools in a broad problem-solving process. High-performance computing facilities make possible the ... [AIP Conf. Proc. 899, 76 (2007)] published Fri Apr 27, 2007.
Direct observation of trapped carriers in polydiacetylene films by optical second harmonic generation
Takaaki Manaka, Hideki Kohn, Yuki Ohshima, Eunju Lim, and Mitsumasa Iwamoto
Trapped carriers in polydiacetylene (PDA) films were directly observed by the electric field induced second harmonic generation (EFISHG) using field effect transistor (FET) structure. Response of EFISHG signal from PDA-FET with applying voltage depended strongly on the polarity of gate voltage. For ... [Appl. Phys. Lett. 90, 171119 (2007)] published Fri Apr 27, 2007.
Large bulk polarization and regular domain structure in ceramic BiFeO[sub 3]
V. V. Shvartsman, W. Kleemann, R. Haumont, and J. Kreisel
Regularly twinned domain structures are observed by scanning piezoforce microscopy on single crystalline grains of BiFeO[sub 3] ceramics being grown by a special low temperature sintering process. The domains are considerably larger than those observed in thin films. Their spontaneous polarization c ... [Appl. Phys. Lett. 90, 172115 (2007)] published Fri Apr 27, 2007.
Continuum theory of a moving membrane
Dan Hu, Pingwen Zhang, and Weinan E
We derive a set of equations for the dynamics of evolving fluid membranes, such as cell membranes, in the presence of bulk fluids. We model the membrane as a surface endowed with a director field, which describes the local average orientation of the molecules on the membrane. A model for the elastic ... [Phys. Rev. E 75, 041605 (2007)] published Thu Apr 26, 2007.
Second harmonic generation in the near field and far field: A sensitive tool to probe crystalline homogeneity
Laurent Mahieu-Williame, Samuel Gresillon, Mireille Cuniot-Ponsard, and Claude Boccara
In order to probe crystalline orientation of Sr[sub x]Ba[sub 1x]Nb[sub 2]O[sub 6] (SBN:x) thin film, we have developed a detection scheme based on a scanning near-field optical microscope (SNOM). It is used to image simultaneously the fundamental and the second harmonic generation (SHG) of light by ... [J. Appl. Phys. 101, 083111 (2007)] published Thu Apr 26, 2007.
Microwave dielectric properties of carbon black filled polymers under uniaxial tension
A. Mdarhri, C. Brosseau, and F. Carmona
Broadband microwave spectroscopy is commonly employed in the determination of the wave transport properties in mesostructured polymers with embedded carbon black particles. However, very little is known on how uniaxial stress affects the effective permittivity of these percolative materials. In this ... [J. Appl. Phys. 101, 084111 (2007)] published Thu Apr 26, 2007.
Spherical nanoindentation and deformation mechanisms in freestanding GaN films
Sandip Basu, Michel W. Barsoum, Adrian D. Williams, and T. D. Moustakas
In this work, spherical nanoindentationwith nanoindenter radius of 1 or 13.5 [mu]mwas used to explore the deformation behavior of GaN freestanding films with two orientations, C (basal) and A (prismatic), grown by hydride vapor phase epitaxy. For the C plane, all the results shown herein and most o ... [J. Appl. Phys. 101, 083522 (2007)] published Thu Apr 26, 2007.
Luminescence and surface properties of Mg[sub x]Zn[sub 1 - x]O thin films grown by pulsed laser deposition
S. Heitsch, G. Zimmermann, D. Fritsch, C. Sturm, R. Schmidt-Grund et al.
We investigated the surface roughness and the luminescence properties of Mg[sub x]Zn[sub 1x]O thin films (0<=x<=0.19). The thin films were grown on a-plane sapphire substrates by pulsed laser deposition. The root-mean-square surface roughness depends on the oxygen partial pressure p(O[sub 2]) applie ... [J. Appl. Phys. 101, 083521 (2007)] published Thu Apr 26, 2007.
Interaction of alkali metals with perylene-3,4,9,10-tetracarboxylic-dianhydride thin films studied by IR spectroscopy
K. Heimer, J. Wuesten, S. Lach, and Ch. Ziegler
In order to clarify the doping behavior of different alkali metals in perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA), Fourier transform infrared spectra of PTCDA thin films doped with sodium, potassium, and cesium were measured and compared. Furthermore the vibrational properties were calcula ... [J. Chem. Phys. 126, 164709 (2007)] published Thu Apr 26, 2007.
Tensile-strained GaAsN quantum dots on InP
P. Pohjola, T. Hakkarainen, H. Koskenvaara, M. Sopanen, H. Lipsanen et al.
Self-assembled quantum dots are typically fabricated from compressive-strained material systems, e.g., InAs on GaAs. In this letter, self-assembled quantum dots from tensile-strained GaAsN on InP are demonstrated. GaAsN on InP has type-I band alignment. Stranski-Krastanov growth mode is not observed ... [Appl. Phys. Lett. 90, 172110 (2007)] published Thu Apr 26, 2007.
Changes in the electronic structures and optical band gap of Ge[sub 2]Sb[sub 2]Te[sub 5] and N-doped Ge[sub 2]Sb[sub 2]Te[sub 5] during phase transition
YoungKuk Kim, K. Jeong, M.-H. Cho, Uk Hwang, H. S. Jeong et al.
Changes in the electronic structures of Ge[sub 2]Sb[sub 2]Te[sub 5] (GST) and N-doped Ge[sub 2]Sb[sub 2]Te[sub 5] film during the phase transition from an amorphous to a crystalline phase were studied using synchrotron radiation high-resolution x-ray photoemission spectroscopy. The changes in tetrah ... [Appl. Phys. Lett. 90, 171920 (2007)] published Thu Apr 26, 2007.
Enhanced response from metal/ZnO bilayer ultraviolet photodetector
Harish Kumar Yadav, K. Sreenivas, and Vinay Gupta
Enhanced ultraviolet (UV) photoresponse is observed in rf magnetron sputtered ZnO thin films interfaced with ultrathin overlayers of different metals (Al, Cu, Sn, Pb, Au, and Te). Electrons transferred from a metal layer to the semiconductor at the interface compensate the surface states and increas ... [Appl. Phys. Lett. 90, 172113 (2007)] published Thu Apr 26, 2007.
How short-range attractions impact the structural order, self-diffusivity, and viscosity of a fluid. [arXiv:0705.0381v1]
ePrint arXiv http://arXiv.org/
Chirality and Equilibrium Biopolymer Bundles. [arXiv:0705.0392v1]
ePrint arXiv http://arXiv.org/
Space-time resolved electrokinetics in cylindrical and semi-cylindrical microchannels. [arXiv:0705.0514v1]
ePrint arXiv http://arXiv.org/
The Glassy Wormlike Chain. [arXiv:0705.0490v1]
ePrint arXiv http://arXiv.org/
Variational bounds for the shear viscosity of gelling melts. [arXiv:cond-mat/0702590v2 UPDATED]
ePrint arXiv http://arXiv.org/