Kumar, K. NaveenNithya, G.Shaik, HabibuddinHemanth, B....
11页查看更多>>摘要：Electrochromics is the emerging technology that is used in sunlight control window glazing for buildings, automobiles and it can also control indoor climate through smart windows. Electrochromism is the mutable change in optical properties of an electrochromic material caused by redox reactions due to the application of voltage. Easy intercalating the H + ions on a dense electrochromic material (WO3) is the most important parameter as far as the reaction kinetics is concerned. The goal of our work is to improve the electrochemical response of electrochromic material by constructing nano-pillars rather than using dense electrochromic materials. Electrochemical performance of both the dense (planar) and porus (nano pillars) structures were simulated and experimentally proved with a systematic discussion in the present work. It is proven and shown here the increase in the electrochemical kinetics through easy diffusion of ions into the nanostructured electrochromic material.
原文链接:
NSTL
Elsevier
Mitra, SrimantaAhmad, AquilChakrabarti, ShamikBiswas, Sajib...
6页查看更多>>摘要：We have synthesized CoFeTiSi quaternary Heusler alloy and experimentally measured its structural and magnetic properties. Detailed ab-initio first principle cal-culations have been performed to investigate the half-metallic behavior of this quaternary Heusler alloy and the effect of disorder on its half-metallicity. The saturation magnetization and Curie temperature are obtained as 1.243 mu B/f.u. and 583 K respectively. The spinwave-stiffness constant (D = 3.259 nm(2)-meV) is obtained from temperature dependence according to Bloch's law. Dynamical stability of the alloy is confirmed from the phonon dispersion curve of the alloy. The first principle calculations show that the alloy is 100% spin-polarized at the Fermi level and the spin-polarization is resistant to the uniform lattice distortion up to a large extent. The effect of anti-site disorder of atoms on the total magnetic moment and the electronic structure is also explored and the moment (and the half-metallicity) is found to be nearly independent (resistant) for the disorders due to Co-Fe and Ti-Si atomic swaps whereas it is affected in case of Co-Si and Fe-Ti atomic swaps. This study reveals that the alloy may be a viable candidate for spintronic applications at room temperature.
原文链接:- NSTL
- Elsevier
Thakre, AtulThakre, NirajChoi, GiheonOh, Seungtaek...
5页查看更多>>摘要：The antiferroelectric Pbcm phase of silver niobate (AgNbO3) has received increasing attention owing to its environmental safety (as it is lead-free), compatibility, and superior energy-storage density compared with its ferroelectric counterparts. We comprehensively investigated the effects of La doping at Ag sites (i.e., Ag0.88La0.12NbO3) on the structural, electronic, and ferroelectric properties of AgNbO3 by using ab initio density functional theory calculations and the Berry phase method for polarization calculations, respectively. The polarization in the [001] direction of pristine AgNbO3 is estimated to be 1.9 mu C/cm2, which is significantly enhanced (to 14.86 mu C/cm2) for Ag0.88La0.12NbO3. The enhancement in the spontaneous polarization of AgNbO3 after the incorporation of La is attributed to suppressed distortion in the Nb-O-Nb antiparallel ordering and tilting of the NbO6 octahedra. Furthermore, the electron density maps of AgNbO3 and its doped counterpart were calculated to investigate the lattice-distortion and bond-change observations.
原文链接:- NSTL
- Elsevier
Bispo, Giordano F. C.Nascimento, Debora S.Santana, Lucas B.Ferreira, Gilvan S....
9页查看更多>>摘要：Lanthanide-doped MgB4O7 is a potential dosimetric material due to its thermoluminescence (TL) and optically stimulated luminescence (OSL) properties. These properties have been largely reported, but there are few theoretical studies dedicated to understanding the materials defects. The aim of this work is to demonstrate that defects are a key issue to understand the luminescence mechanisms. A new set of interatomic potential parameters were obtained reproducing the MgB4O7 structure better than 2% and 4% for oxide precursors. The results showed that the O Frenkel defect is the most probable which can account for the intrinsic blue emission in the undoped material. Also, the extrinsic defect calculations demonstrated two possible doping schemes for lanthanide ions. One lanthanide dopant group prefers the direct substitution at the boron site with a molecular ion of (BO3)(-3) moving to balance the strain caused by this substitution. Another prefers a substitution at the magnesium site with an MgB anti-site as the charge compensation defect.
原文链接:- NSTL
- Elsevier
Luo, BenlongSa, RongjianLiu, Diwen
5页查看更多>>摘要：In the present study, first-principles calculations are performed to study the structural, elastic, electronic, and optical properties of Ag2ZnSnSe4 (AZTSe) and Ag1.5Na0.5ZnSnSe4 (ANZTSe) for the first time. The dopant formation energy and phonon dispersion ensure the thermodynamic stability of ANZTSe. The tendency of phase separation still exists for ANZTSe. In addition, the mechanical stability of ANZTSe is confirmed. The electronic and optical properties of AZTSe and ANZTSe are analyzed by employing the hybrid functional PBE0. The results show that the substitution of Na for Ag results in the increasing band gap of AZTSe. ANZTSe is a direct bandgap compound with the value of 1.54 eV. It is found that AZTSe and ANZTSe have low carrier effective masses and show good mobility. The visible light absorption capacity of ANZTSe is slightly lower than that of AZTSe. In general, ANZTSe is the potential candidate for solar cells.
原文链接:- NSTL
- Elsevier
Tsay, Chien-YieChen, Yun-ChiTsai, Hsuan-MengHsu, Cheng-Liang...
10页查看更多>>摘要：Solar-blind ultraviolet (UV) photodetectors with an amorphous zinc-tin oxide (a-ZTO) sensing layer have been fabricated on alkali-free glass substrates by a sol-gel method and spin coating technique. The as-prepared a-ZTO semiconductor thin films are highly transparent (> 88.5%) in the visible region and exhibit moderate electrical properties at room temperature. The effects of changes in the asymmetry ratio of the line-width of a pair of Al interdigitated electrodes on the photoelectrical characteristics of solution-processed a-ZTO metal-semiconductor-metal(MSM) UV photodetectors was investigated. These photodetector devices had good photosensing properties, and their current-voltage (I-V) characteristic exhibited obvious rectification behavior under UV light illumination when operated at bias voltages of-3 V-3 V. Experimental results showed that the responsivity and specific detectivity of the a-ZTO MSM photodetectors increased with increases in the asymmetry ratio of a pair of Al interdigital electrodes. The a-ZTO MSM UV photodetector operated at 3 V bias voltage had the best responsivity of 7.42 mA/W and the highest specific detectivity of 6.35 x 10(7) J when the asymmetry ratio of electrodes was 10:1.
原文链接:- NSTL
- Elsevier
Akin, HasanUlusoy, Suleyman
6页查看更多>>摘要：We consider q-state Potts model in the presence of competing two nearest interactions and prolonged next nearest interactions on a Cayley tree of order two. We derive the recursion relations, which determine the free energy of a q-state Potts model on the Cayley tree. We exactly solve the phase transitions problem for the model, namely we calculate the critical surface such that there is a phase transition above it, and a single Gibbs state found elsewhere. We study the periodicity of the phases (Gibbs measures) by means of Lyapunov exponents.
原文链接:- NSTL
- Elsevier
Al-Ta'ii, Hassan M. JaberIjam, Ali
4页查看更多>>摘要：In this work, the influence of the alpha energy level on the Al/DNA/Al Schottky diode was examined through J-V curve. The diodes were exposed to alpha radiation energy ranging from 0.625 MeV to 5.485 MeV under the same irradiation time. Diode parameters, such as series and shunt resistance, were determined by using a conventional method. The current density and electrical conductivity were also tested. From the results, it is observed that the series resistance for the irradiated samples is found to be higher than the non-radiated one, and its behavior is approximately equivalent to the hypersensitivity phenomena. The current density, for all samples, increases with increasing the electric field. Furthermore, the electrical conductivity of the non-radiated sample was higher than the alpha irradiated samples at a voltage of 6.0 V. These results highlight the significance of using this device as a detector for alpha particles' radiation in bioelectronics applications.
原文链接:- NSTL
- Elsevier
Mahato, Dev K.Molak, AndrzejGruszka, IrenaWiniarski, Antoni...
11页查看更多>>摘要：A solid-state reaction was applied to obtain lanthanum nickelate manganate ceramics. This double perovskite was sintered at T-S = 1350 degrees C. An occurrence of monoclinic P2(1)/n major phase of La2NiMnO6 at room temperature was confirmed by X-ray diffraction analysis. The minor phase of cubic Fm-3m of the MnNi6O8 phase was detected. Scanning electron microscopy (SEM) images exhibited agglomerated irregular grains of sizes ranging from similar to 1 to 5 mu m, separated by voids. The energy dispersion X-ray spectroscopy (EDS) method confirmed the occurrence of La, Mn, Ni, and O elements and the absence of other atoms. The Nyquist plots exhibited overlapped semi-circular-like arcs, attributed to grain and grain boundary effects at low temperature range. The imaginary impedance peak, which shifted when temperature and frequency increased, was attributed to the relaxation process. The activation energy E-a,E-tau = 0.10 eV and characteristic relaxation time tau(0) = 1.49 ps for the relaxation process was estimated. The Bode plot helped to discern different mechanisms involved in the impedance observed in the low-temperature range. The conductivity scaling behavior confirmed the hopping mechanism of the small polarons. The estimated dc electrical conductivity activation energy, E-dc, varied from 0.13 eV to 0.17 eV, depending on the temperature range. Variable range hopping of the small polaron model consistent with the structural disorder was appropriate in the low-temperature range. The dielectric loss response was explained in the framework of the conductivity effect. The non-coincidence of the peak positions of impedance Z '' and modulus M '' spectra confirmed the short-range motion of charge carriers. The manifestation of the magneto dielectric effect was deduced.
原文链接:- NSTL
- Elsevier
