Advances in Condensed Matter Physics https://www.hindawi.com The latest articles from Hindawi © 2017 , Hindawi Limited . All rights reserved. Unprecedented Integral-Free Debye Temperature Formulas: Sample Applications to Heat Capacities of ZnSe and ZnTe Mon, 18 Sep 2017 00:00:00 +0000 http://www.hindawi.com/journals/acmp/2017/9321439/ Detailed analytical and numerical analyses are performed for combinations of several complementary sets of measured heat capacities, for ZnSe and ZnTe, from the liquid-helium region up to 600 K. The isochoric (harmonic) parts of heat capacities, , are described within the frame of a properly devised four-oscillator hybrid model. Additional anharmonicity-related terms are included for comprehensive numerical fittings of the isobaric heat capacities, . The contributions of Debye and non-Debye type due to the low-energy acoustical phonon sections are represented here for the first time by unprecedented, integral-free formulas. Indications for weak electronic contributions to the cryogenic heat capacities are found for both materials. A novel analytical framework has been constructed for high-accuracy evaluations of Debye function integrals via a couple of integral-free formulas, consisting of Debye’s conventional low-temperature series expansion in combination with an unprecedented high-temperature series representation for reciprocal values of the Debye function. The zero-temperature limits of Debye temperatures have been detected from published low-temperature data sets to be significantly lower than previously estimated, namely, 270 (±3) K for ZnSe and 220 (±2) K for ZnTe. The high-temperature limits of the “true” (harmonic lattice) Debye temperatures are found to be 317 K for ZnSe and 262 K for ZnTe. R. Pässler Copyright © 2017 R. Pässler. All rights reserved. Surface Plasmon Resonance Enhanced Spontaneous Upconversion and Stimulated Emissions in Glass Ceramics Containing Ba2LaF7 Nanocrystals Wed, 13 Sep 2017 00:00:00 +0000 http://www.hindawi.com/journals/acmp/2017/5304791/ Glass ceramics containing Yb3+, Er3+ codoped Ba2LaF7 nanocrystals were fabricated via melt quenching method and the subsequent heating treatment. The formation of Ba2LaF7 nanocrystals in the glass ceramics was confirmed by X-ray diffraction (XRD) and transmission electron microscope (TEM). The spontaneous upconversion (UC) emission and the stimulated counterpart as a random lasing action of Er3+, which were related to the characteristic transitions of Er3+ ions, were achieved in the Yb3+, Er3+-doped Ba2LaF7 nanocrystals embedded glass ceramic hybrid. Furthermore, the absorption spectra verified the surface plasmon resonance (SPR) band of Ag, which precipitated from the matrix glasses as Ag nanoparticles (NPs). By incorporating Ag NPs in the glass ceramic hybrid, spontaneous UC emission intensity of Er3+ in visible region was significantly enhanced, while the threshold of the random lasing was decreased from 480 to 350 nJ/cm2. Sai Li, Wei Lu, Qihua Yang, Dacheng Zhou, Jianbei Qiu, Xuhui Xu, and Xue Yu Copyright © 2017 Sai Li et al. All rights reserved. Structural Characterization of Natural and Processed Zircons with X-Rays and Nuclear Techniques Sun, 10 Sep 2017 08:06:44 +0000 http://www.hindawi.com/journals/acmp/2017/9707604/ In ceramic industry, zircon sand is widely used in different applications because zirconia plays a role as common opacifying constituent. In particular, it is used as a basic component of glazes applied to ceramic tiles and sanitary ware as well as an opacifier in unglazed bulk porcelain stoneware. Natural zircon sands are the major source of zirconium minerals for industrial applications. In this paper, long, medium, and short range studies were conducted on zirconium minerals originated from Australia, South Africa, and United States of America using conventional and less conventional techniques (i.e., X-Ray Diffraction (XRD), Positron Annihilation Lifetime Spectroscopy (PALS), and Perturbed Angular Correlations (PAC)) in order to reveal the type and the extension of the regions that constitute the metamict state of zircon sands and the modifications therein produced as a consequence of the industrial milling process and the thermal treatment in the production line. Additionally, HPGe gamma-ray spectroscopy confirms the occurrence of significant levels of natural radioactivity responsible for metamictization in the investigated zircon samples. Results from XRD, PALS, and PAC analysis confirm that the metamict state of zircon is a dispersion of submicron disordered domains in a crystalline matrix of zircon. Laura C. Damonte, Patricia C. Rivas, Alberto F. Pasquevich, Fernanda Andreola, Federica Bondioli, Anna M. Ferrari, Laura Tositti, and Giorgia Cinelli Copyright © 2017 Laura C. Damonte et al. All rights reserved. Dynamics of Dispersive Wave Generation in Gas-Filled Photonic Crystal Fiber with the Normal Dispersion Wed, 30 Aug 2017 00:00:00 +0000 http://www.hindawi.com/journals/acmp/2017/1268230/ The absence of Raman and unique pressure-tunable dispersion is the characteristic feature of gas-filled photonic crystal fiber (PCF), and its zero dispersion points can be extended to the near-infrared by increasing gas pressure. The generation of dispersive wave (DW) in the normal group velocity dispersion (GVD) region of PCF is investigated. It is demonstrated that considering the self-steepening (SS) and introducing the chirp of the initial input pulse are two suitable means to control the DW generation. The SS enhances the relative average intensity of blue-shift DW while weakening that of red-shift DW. The required propagation distance of DW emission is markedly varied by introducing the frequency chirp. Manipulating DW generation in gas-filled PCF by the combined effects of either SS or chirp and three-order dispersion (TOD) provides a method for a concentrated transfer of energy into the targeted wavelengths. Zhixiang Deng and Meng Zhang Copyright © 2017 Zhixiang Deng and Meng Zhang. All rights reserved. Theoretical Study on Effect of Defective Connection to Reservoirs in an Atomic-Scale Conductor Mon, 21 Aug 2017 08:43:14 +0000 http://www.hindawi.com/journals/acmp/2017/2857393/ We theoretically investigate the effect of a defect at the interface between a conductor and reservoirs in an atomic-scale device. Since fabrication of atomic-scale contacts is a complex task, there could be defects at the interface between the conductor and reservoirs. Such defective contacts will make it difficult to measure currents properly. In this paper, we calculate current-voltage characteristics in two-dimensional devices with a defective connection to reservoirs by using the nonequilibrium Green’s function method. Results show that the magnitude of resistance change depends on the amplitude of quantized wave functions at the position of the defect. Masato Morifuji Copyright © 2017 Masato Morifuji. All rights reserved. Resonance Raman Scattering in TlGaSe2 Crystals Sun, 20 Aug 2017 07:35:42 +0000 http://www.hindawi.com/journals/acmp/2017/5787821/ The resonance Raman scattering for geometries and at temperature 10 K and infrared reflection spectra in and polarizations at 300 K were investigated. The number of () and () symmetry vibrational modes observed experimentally and calculated theoretically agree better in this case than when TlGa2Se4 crystals belong to symmetry group. The emission of resonance Raman scattering and excitonic levels luminescence spectra overlap. The lines in resonance Raman spectra were identified as a combination of optical phonons in Brillouin zone center. N. N. Syrbu, A. V. Tiron, V. V. Zalamai, and N. P. Bejan Copyright © 2017 N. N. Syrbu et al. All rights reserved. Torsional Potential Energy Surfaces of Dinitrobenzene Isomers Sun, 20 Aug 2017 00:00:00 +0000 http://www.hindawi.com/journals/acmp/2017/3296845/ The torsional potential energy surfaces of 1,2-dinitrobenzene, 1,3-dinitrobenzene, and 1,4-dinitrobenzene were calculated using the B3LYP functional with 6-31G(d) basis sets. Three-dimensional energy surfaces were created, allowing each of the two C-N bonds to rotate through 64 positions. Dinitrobenzene was chosen for the study because each of the three different isomers has widely varying steric hindrances and bond hybridization, which affect the energy of each conformation of the isomers as the nitro functional groups rotate. The accuracy of the method is determined by comparison with previous theoretical and experimental results. The surfaces provide valuable insight into the mechanics of conjugated molecules. The computation of potential energy surfaces has powerful application in modeling molecular structures, making the determination of the lowest energy conformations of complex molecules far more computationally accessible. Paul M. Smith and Mario F. Borunda Copyright © 2017 Paul M. Smith and Mario F. Borunda. All rights reserved. Absorption Spectrum and Density of States of Square, Rectangular, and Triangular Frenkel Exciton Systems with Gaussian Diagonal Disorder Mon, 14 Aug 2017 09:45:48 +0000 http://www.hindawi.com/journals/acmp/2017/3836204/ Using the coherent potential approximation, we investigate the effects of disorder on the optical absorption and the density of states of Frenkel exciton systems on square, rectangular, and triangular lattices with nearest-neighbor interactions and a Gaussian distribution of transition energies. The analysis is based on an elliptic integral approach that gives results over the entire spectrum. The results for the square lattice are in good agreement with the finite-array calculations of Schreiber and Toyozawa. Our findings suggest that the coherent potential approximation can be useful in interpreting the optical properties of two-dimensional systems with dominant nearest-neighbor interactions and Gaussian diagonal disorder provided the optically active states are Frenkel excitons. Ibrahim Avgin and David Huber Copyright © 2017 Ibrahim Avgin and David Huber. All rights reserved. Dispersion of Switching Processes in Ferroelectric Ceramics Mon, 03 Jul 2017 08:25:44 +0000 http://www.hindawi.com/journals/acmp/2017/2507808/ The influence of the switching processes on self-heating of ferroelectric PZT ceramics samples was studied in high-amplitude sine and meander electric fields in a wide frequency range of 50 to 1500 Hz. It is shown that the linear dependence of the self-heating temperature on the electric field frequency is observed only in low-frequency region. It was found that there exists a maximum on the frequency dependence of the self-heating temperature. The critical frequency corresponding to this maximum depends on both the properties of the material and geometry of the sample. O. V. Malyshkina, Anton Yurievich Eliseev, and R. M. Grechishkin Copyright © 2017 O. V. Malyshkina et al. All rights reserved. Surfactant Assisted Stabilization of Carbon Nanotubes Synthesized by a Spray Pyrolysis Method Sun, 02 Jul 2017 08:32:15 +0000 http://www.hindawi.com/journals/acmp/2017/1751768/ Surface modification of carbon nanotubes has been an interesting issue from a composites materials point of view. A nanotubes agglomeration has to be avoided to achieve a homogeneous dispersion in a composite matrix. In this research, we report on the synthesis of carbon nanotubes using a variant of the chemical vapor deposition technique known as spray pyrolysis method. X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) studies showed that the synthesized products had an aligned structure with low purity degree, high content of catalyst particles, and a smaller amount of amorphous carbon. A secondary method was applied, which involves an acidic treatment that dissolves contaminant particles to enhance the purity of the nanotubes. Microstructural analysis, which includes XRD and SEM, indicates an effective reduction of impurities. Dispersion of the nanotubes was assessed using different surfactants, such as sodium dodecyl-sulfate (SDS) and ethylenediaminetetraacetic acid (EDTA). Finally, Raman spectroscopy, UV-Vis, and SEM techniques confirm that better results were obtained with EDTA. For EDTA and SDS surfactants, low concentrations of 0.3 mg/mL and 0.2 mg/mL were most efficient, respectively. D. Mendoza-Cachú, C. Mercado-Zúñiga, and G. Rosas Copyright © 2017 D. Mendoza-Cachú et al. All rights reserved. Optical Orbital Angular Momentum Demultiplexing and Channel Equalization by Using Equalizing Dammann Vortex Grating Wed, 21 Jun 2017 00:00:00 +0000 http://www.hindawi.com/journals/acmp/2017/6293910/ A novel equalizing Dammann vortex grating (EDVG) is proposed as orbital angular momentum (OAM) multiplexer to realize OAM signal demultiplexing and channel equalization. The EDVG is designed by suppressing odd diffraction orders and adjusting the grating structure. The light intensity of diffraction is subsequently distributed evenly in the diffraction orders, and the total diffraction efficiency can be improved from 53.22% to 82%. By using the EDVG, OAM demultiplexing and channel equalization can be realized. Numerical simulation shows that the bit error rate (BER) of each OAM channel can decrease to when the bit SNR is 22 dB, and the intensity is distributed over the necessary order of diffraction evenly. Mingyang Su, Junmin Liu, Yanliang He, Shuqing Chen, and Ying Li Copyright © 2017 Mingyang Su et al. All rights reserved. Phase Transitions and Magnetocaloric Properties in MnCo1−xZrxGe Compounds Tue, 13 Jun 2017 07:38:54 +0000 http://www.hindawi.com/journals/acmp/2017/2683789/ The structural, magnetic, and magnetocaloric properties of () have been studied through X-ray diffraction, differential scanning calorimetry, and magnetization measurements. Results indicate that the partial substitution of Zr for Co in decreases the martensitic transition temperature (). For = 0.02, was found to coincide with the ferromagnetic transition temperature () resulting in a first-order magnetostructural transition (MST). A further increase in zirconium concentration ( = 0.04) showed a single transition at . The MST from the paramagnetic to ferromagnetic state results in magnetic entropy changes () of 7.2 J/kgK for = 5 T at 274 K for = 0.02. The corresponding value of the relative cooling power (RCP) was found to be 266 J/kg for = 5 T. The observed large value of MCE and RCP makes this system a promising material for magnetic cooling applications. Anil Aryal, Abdiel Quetz, Sudip Pandey, Igor Dubenko, Shane Stadler, and Naushad Ali Copyright © 2017 Anil Aryal et al. All rights reserved. Synthesis of a Novel Ce-bpdc for the Effective Removal of Fluoride from Aqueous Solution Mon, 12 Jun 2017 00:00:00 +0000 http://www.hindawi.com/journals/acmp/2017/8305765/ Ce-1,1′-biphenyl-4,4′-dicarboxylic acid (Ce-bpdc), a novel type of metal organic framework, was synthesized and applied to remove excessive fluoride from water. The structure and morphology of Ce-bpdc were measured by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The effects, such as saturated adsorption capacity, , and pH, were investigated. The optimal pH value for fluoride adsorption was the range from 5 to 6. The coexisting bicarbonate anions have a little influence on fluoride removal. The fluoride adsorption over the Ce-bpdc adsorbent could reach its equilibrium in about 20 min. The Ce-bpdc coordination complex exhibited high binding capacity for fluoride ions. The maximum adsorption capacity calculated from Langmuir model was high up to 45.5 mg/g at 298 K (pH = 7.0) and the removal efficiency was greater than 80%. In order to investigate the mechanism of fluoride removal, various adsorption isotherms such as Langmuir and Freundlich were fitted. The experimental data revealed that the Langmuir isotherm gave a more satisfactory fit for fluoride removal. Finally, the tested results of ground water samples from three places, Yuefang, Jiangji, and Sanyi which exhibited high removal efficiency, also demonstrate the potential utility of the Ce-bpdc as an effective adsorbent. Changqing Zhao, Yanwei Cui, Fang Fang, Si Ok Ryu, and Jiarui Huang Copyright © 2017 Changqing Zhao et al. All rights reserved. Excitation Spectrum of the Néel Ensemble of Antiferromagnetic Nanoparticles as Revealed in Mössbauer Spectroscopy Sun, 11 Jun 2017 06:41:05 +0000 http://www.hindawi.com/journals/acmp/2017/6209206/ The excitation spectrum of the Néel ensemble of antiferromagnetic nanoparticles with uncompensated magnetic moment is deduced in the two-sublattice approximation following the exact solution of equations of motion for magnetizations of sublattices. This excitation spectrum represents four excitation branches corresponding to the normal modes of self-consistent regular precession of magnetizations of sublattices and the continuous spectrum of nutations of magnetizations accompanying these normal modes. Nontrivial shape of the excitation spectrum as a function of the value of uncompensated magnetic moment corresponds completely to the quantum-mechanical calculations earlier performed. This approach allows one to describe also Mössbauer absorption spectra of slowly relaxing antiferromagnetic and ferrimagnetic nanoparticles and, in particular, to give a phenomenological interpretation of macroscopic quantum effects observed earlier in experimental absorption spectra and described within the quantum-mechanical representation. Mikhail A. Chuev Copyright © 2017 Mikhail A. Chuev. All rights reserved. Fast Switching 4H-SiC P-i-n Structures Fabricated by Low Temperature Diffusion of Al Tue, 30 May 2017 00:00:00 +0000 http://www.hindawi.com/journals/acmp/2017/7820676/ P-i-n 4H-SiC diode structures are fabricated by a new approach which is low temperature diffusion of aluminium (Al) in SiC using flow of vacancy defects from surface into volume of crystal. In conventional diffusion in SiC, the operating temperature is usually >2050°C while, in this approach, the diffusion temperature is between 1150 and 1300°C. As the conditions of formation of junction in this method essentially differ from conventional diffusion (low temperature and process of diffusion are accompanied by forming structure defects), it is interesting to identify the advantages and disadvantages of a new method of diffusion. Fabricated p-i-n structures have low breakdown voltage between 80 and 140 V (due to the influence of dislocations and micropipes) and are capable of operating at temperatures up to 300°C. Structure has fast switching time and duration of the reverse recovery current less than 10 ns. We believe that because of low diffusion temperature, the concentration of nitrogen related trapping levels is relatively low and as a result the fast switching time is observed in our samples. It has been shown that this low temperature diffusion technology can be used to fabricate -region and high resistive -region of SiC diode in single-step process. I. G. Atabaev, Kh. N. Juraev, and V. A. Pak Copyright © 2017 I. G. Atabaev et al. All rights reserved. Amorphization Effect for Kondo Semiconductor CeRu2Al10 Wed, 24 May 2017 07:57:39 +0000 http://www.hindawi.com/journals/acmp/2017/9848151/ We measured the magnetic susceptibility , electrical resistivity , and specific heat of a sputtered amorphous (a-)CeRu2Al10 alloy. value for a-CeRu2Al10 alloy follows a Curie-Weiss paramagnetic behavior in the high-temperature region, and magnetic transition was not observed down to 2 K. The effective paramagnetic moment is 1.19 /Ce-atom. The resistivity shows a typical disordered alloy behavior, that is, small temperature dependence for the whole temperature range. We observed an enhancement of and in the low-temperature region of  K. The enhancement in is suppressed by applying a magnetic field. It is suggested that this behavior is caused by the Kondo effect. Yusuke Amakai, Yasuhiro Shiojiri, Kei Ishihara, Hiroto Hitotsukabuto, Shigeyuki Murayama, Naoki Momono, and Hideaki Takano Copyright © 2017 Yusuke Amakai et al. All rights reserved. Resonant Scattering and Energy Relaxation in Quantum Dot Systems Thu, 11 May 2017 07:34:11 +0000 http://www.hindawi.com/journals/acmp/2017/4396915/ We propose a new Auger-like mechanism for energy relaxation in quantum dots (QD) driven by resonant scattering of delocalized wetting layer (WL) carriers. It is demonstrated that resonant scattering leads to a considerable increase in the relaxation rate that can explain experimentally obtained relaxation rates. Analytical results for the relaxation rate are obtained for rectangular dots revealing a weak logarithmic dependence on the dot depth and level density. Comparing results for a rectangular and a parabolic QD model we conclude that the relaxation rate is not very sensitive to a chosen model. I. A. Larkin and A. Vagov Copyright © 2017 I. A. Larkin and A. Vagov. All rights reserved. Characteristic Evaluation of Organic Light-Emitting Diodes Prepared with Stamp Printing Technique Wed, 10 May 2017 08:16:59 +0000 http://www.hindawi.com/journals/acmp/2017/2414798/ We have reported on a stamp printing technique that uses PET release film as a printing stamp to deposit TPBi thin film served as the electron transport layer of the organic light-emitting diodes. TPBi thin film was printed with a good uniformity and resolution. Effect of deposition conditions on optical and electrical properties and surface roughness of TPBi thin film have been studied under spectroscopy and atomic force microscopy, respectively. It is found that characteristic of TPBi thin film is improved via controlled stamp temperature and time. Since TPBi thin film exhibits the surface morphology comparable to that of conventional spin-coating thin film, our findings suggest that PET release film-based stamp printing approach is possible to use as an alternative deposition of the organic thin film as compared with a traditional one. Apisit Chittawanij and Kitsakorn Locharoenrat Copyright © 2017 Apisit Chittawanij and Kitsakorn Locharoenrat. All rights reserved. Light Polarization Using Ferrofluids and Magnetic Fields Tue, 09 May 2017 00:00:00 +0000 http://www.hindawi.com/journals/acmp/2017/2583717/ We are presenting an experimental setup based on polarized light, enabling the visualization of the magnetic field of magnetic assemblies using a Hele-Shaw cell filled with ferrofluids. We have simulated the observed patterns with hypergeometric polynomials. Alberto Tufaile, Timm A. Vanderelli, and Adriana Pedrosa Biscaia Tufaile Copyright © 2017 Alberto Tufaile et al. All rights reserved. Stability and Dissipation of Many Components’ Systems and Application to Metamaterials Sun, 30 Apr 2017 13:09:46 +0000 http://www.hindawi.com/journals/acmp/2017/8963839/ Dykhne’s method, based on rotational symmetry of two-dimensional equations of constant direct current, was applied to study the properties of the medium, consisting of reactances—of inductors and capacitors (nondissipative elements). The exact solution for the 4-component system consisting of the two different types of 2 inductors and 2 capacitors, randomly placed and connected, was obtained. The obtained solution for investigated system has the two features: (1) the finite dissipation in the nondissipative system of inductors and capacitors; (2) appearance of plateau—the constant value of effective conductivity in a wide range of concentrations of components. The obtained results were useful for description of composite metamaterials. Valeriy E. Arkhincheev Copyright © 2017 Valeriy E. Arkhincheev. All rights reserved. Magnetic Properties of Sm-Fe-N/Co-B Composite Magnets Prepared by Chemical Reduction Mon, 24 Apr 2017 00:00:00 +0000 http://www.hindawi.com/journals/acmp/2017/7648373/ An attempt was made to produce Sm-Fe-N/Co-B composite magnets by chemical reduction. It was found that a composite powder consisting of Sm-Fe-N particles coated with fine Co-B particles could be obtained by chemical reduction. The Sm-Fe-N/Co-B composite powder acted as a single hard magnetic phase and showed a smooth hysteresis loop. The composite powder exhibited a higher remanence of 93.1 Am2/kg and a higher coercivity of 0.45 MA/m than a mixture of the Sm-Fe-N powder and Co-B powder prepared by a similar procedure but using a higher concentration of aqueous solution for the chemical reduction. Tetsuji Saito Copyright © 2017 Tetsuji Saito. All rights reserved. Stability of Bar Code Information Stored in Magnetic Nanowire Arrays Wed, 19 Apr 2017 09:24:12 +0000 http://www.hindawi.com/journals/acmp/2017/4396015/ Firmware applications such as security codes, magnetic keys, and similar products can be stored in magnetic bar codes similar to optical bar codes. This can be achieved on the triangular lattice present in porous alumina, whose pori can be filled by magnetic material, over which magnetic bar codes can be inscribed. We study the conditions to improve the durability of the stored information by minimizing the repulsive energy among wires with parallel magnetization within the same bar but interacting with attractive energy with wires in the neighboring bar. The following parameters are varied to minimize the energy of the system: relative amount of magnetization orientation within the bar code area in any orientation, width of the bars, and distribution of wider bars to the outside or to the inside of the code. It is found that durability of the code is favored for equal amount of magnetization in each direction, abundance of narrow bars trying to locate a few wider ones towards the center. Three real commercial optical bar codes taken at random were mapped into magnetic bar codes; it is found that the corresponding magnetic energies are similar to those analyzed here which provides a realistic test for this approach. Eduardo Cisternas, Eugenio E. Vogel, and Julián Faúndez Copyright © 2017 Eduardo Cisternas et al. All rights reserved. Intrinsic and Extrinsic Ferromagnetism in Co-Doped Indium Tin Oxide Revealed Using X-Ray Magnetic Circular Dichroism Thu, 13 Apr 2017 06:44:35 +0000 http://www.hindawi.com/journals/acmp/2017/2836254/ The effects of high-temperature annealing on ferromagnetic Co-doped Indium Tin Oxide (ITO) thin films have been investigated using X-ray diffraction (XRD), magnetometry, and X-Ray Magnetic Circular Dichroism (XMCD). Following annealing, the magnetometry results indicate the formation of Co clusters with a significant increase in the saturation magnetization of the thin films arising from defects introduced during cluster formation. However, sum rule analysis of the element-specific XMCD results shows that the magnetic moment at the Co sites is reduced after annealing. The effects of annealing demonstrate that the ferromagnetism observed in the as-deposited Co-doped ITO films arises from intrinsic defects and cannot be related to the segregation of metallic Co clusters. A. M. H. R. Hakimi, F. Schoofs, M. G. Blamire, S. Langridge, and S. S. Dhesi Copyright © 2017 A. M. H. R. Hakimi et al. All rights reserved. The Tunnelling Current through Oscillating Resonance and the Sisyphus Effect Tue, 11 Apr 2017 00:00:00 +0000 http://www.hindawi.com/journals/acmp/2017/2435857/ The tunnelling current through an oscillating resonance level is thoroughly investigated exactly numerically and with several approximations—analytically. It is shown that while the oscillations can increase the tunnelling current (and in several cases the increase is exponentially large), their main effect is to reduce it dramatically at certain energies. In fact, the current in the presence of the oscillations cannot increase the maximum current of the adiabatic solution. That is why, while the elevator effect does occur in this system, the Sisyphus effect is the more dominant and prominent one. Er’el Granot Copyright © 2017 Er’el Granot. All rights reserved. Study of Low Voltage Prebreakdown Sites in Multicrystalline Si Based Cells by the LBIC, EL, and EDS Methods Mon, 10 Apr 2017 00:00:00 +0000 http://www.hindawi.com/journals/acmp/2017/1946490/ Breakdown sites in multicrystalline Si solar cells have been studied by reverse-bias electroluminescence, electron beam induced current (EBIC) and laser beam induced current (LBIC), and Energy Dispersive X-Ray Spectroscopy methods. In the breakdown sites revealed by EL at small reverse bias (~5 V), the enhanced aluminum and oxygen concentration is revealed. Such breakdowns can be located inside the depletion region because they are not revealed by the EBIC or LBIC methods. Breakdowns revealed by EL at larger bias correlate well with extended defects in the EBIC and LBIC images. V. I. Orlov, E. B. Yakimov, E. P. Magomedbekov, and A. B. Danilin Copyright © 2017 V. I. Orlov et al. All rights reserved. Design and Fabrication of a Novel Wideband DNG Metamaterial with the Absorber Application in Microwave X-Band Sun, 26 Mar 2017 00:00:00 +0000 http://www.hindawi.com/journals/acmp/2017/1279849/ A novel metamaterial, which exhibits a wideband double negative behavior in X-band, is proposed, designed, and investigated in this paper. The metamaterial is composed of modified S-shaped split-ring resonators (S-SRR). The periodic structure is designed and simulated using CST MWs. Next, the experiments are carried out, and it is shown that the simulation and the experimental results agree well and the designed structure has a wide bandwidth in X-band. An absorber application of this metamaterial is also provided, and the structure can be used as an absorber with absorption rate of over 80% for the polarization angles between 0° and 40°. Ahmed Mahmood, Gölge Ögücü Yetkin, and Cumali Sabah Copyright © 2017 Ahmed Mahmood et al. All rights reserved. Influence of Pressure on the Temperature Dependence of Quantum Oscillation Phenomena in Semiconductors Mon, 20 Mar 2017 00:00:00 +0000 http://www.hindawi.com/journals/acmp/2017/6747853/ The influence of pressure on the oscillations of Shubnikov-de Haas (ShdH) and de Haas-van Alphen (dHvA) in semiconductors is studied. Working formula for the calculation of the influence of hydrostatic pressure on the Landau levels of electrons is obtained. The temperature dependence of quantum oscillations for different pressures is determined. The calculation results are compared with experimental data. It is shown that the effect of pressure on the band gap is manifested to oscillations and ShdH and dHvA effects in semiconductors. G. Gulyamov, U. I. Erkaboev, and A. G. Gulyamov Copyright © 2017 G. Gulyamov et al. All rights reserved. Geometrically Tunable Transverse Electric Field in Multilayered Structures Wed, 15 Mar 2017 06:34:27 +0000 http://www.hindawi.com/journals/acmp/2017/1216867/ Appearance of a transverse component in dc electric field with respect to the applied current is investigated in periodic multilayer composite structures made of nanometer-to-micrometer scale alternating layers of two different homogeneous and isotropic conducting materials. Dependence of the transverse electric field on geometrical orientation of the layers is examined using the coordinate transformation approach. Electric field bending angle as a function of the layers’ resistivity ratio is studied in detail. It is shown that both the direction and the magnitude of the field can be changed using orientation angle of the layers as a tuning parameter. Roland H. Tarkhanyan and Dimitris G. Niarchos Copyright © 2017 Roland H. Tarkhanyan and Dimitris G. Niarchos. All rights reserved. Corrigendum to “Impact of Pressure and Brine Salinity on Capillary Pressure-Water Saturation Relations in Geological CO2 Sequestration” Tue, 14 Mar 2017 00:00:00 +0000 http://www.hindawi.com/journals/acmp/2017/5367087/ Jongwon Jung and Jong Wan Hu Copyright © 2017 Jongwon Jung and Jong Wan Hu. All rights reserved. Lattice Dynamics and Transport Properties of Multiferroic DyMn2O5 Tue, 07 Mar 2017 00:00:00 +0000 http://www.hindawi.com/journals/acmp/2017/5389573/ We have investigated the optical and electrical properties of polycrystalline DyM synthesized by sol-gel method. Analysis of the reflectivity spectrum has led to the observation of 18 infrared (IR) active phonon modes out of 36 predicted ones. We discuss the results in terms of different phonon bands originated as a result of atomic vibrations. Moreover, the optical energy band gap of  eV has been estimated from optical conductivity spectrum. The energy band gap and optical transitions were also determined from UV-visible absorption spectrum and band gap of  eV was estimated. Moreover, DC electrical resistivity shows the p-type polaronic conduction above room temperature. Javed Ahmad, Syed Hamad Bukhari, M. Tufiq Jamil, Mehr Khalid Rehmani, Hammad Ahmad, and Tahir Sultan Copyright © 2017 Javed Ahmad et al. All rights reserved.