Rauf, Hibba-tuYasmin, NaziaAli, GhulamAshiq, Muhammad Naeem...
6页查看更多>>摘要：Cerium oxide, sulfide and composites of cerium sulfide-cerium oxide were prepared by co-precipitation technique. The fabricated samples were characterized by XRD. The photocatalytic degradation of synthesized samples was made to check their catalytic performance. The results of photocatalytic activity verified that 94% degradation of the rhodamine B dye took place in presence of catalyst (composite of cerium oxide/sulfide) and UV-visible irradiation, whereas in catalyst absence, percentage degradation of rhodamine B dye was less than 15% at the end of 120 min. The composite of cerium oxide/sulfide showed greater photo degradation (94%) with rhodamine B dye under UV irradiation than cerium oxide (80%) and cerium sulfide (71%). Percentage degradation of composite materials was greater due to the band gap because photo catalysis depends upon the band gap energy. Band gap energy for composite of cerium oxide/sulfide may be calculated by Tauc relationship. Photo degradation reaction obeyed the rules of pseudo-first-order kinetic reaction.
原文链接:
NSTL
Elsevier
El-Bana, M. S.El Radaf, I. M.
12页查看更多>>摘要：CuSbSe2 (CSS2) films were obtained via the electron beam deposition approach. The XRD data of the as-prepared CSS2 thin films revealed an amorphous state. Whereas the CSS2 film annealed at 260 degrees C for 1 h displayed a polycrystalline nature with an orthorhombic system. The Swanepoel approach has been utilized to determine the optical constants. All films exhibit p-type semiconducting behaviour. Also, they reveal allowed indirect transition with an energy gap (1.13-1.10 eV). Moreover, they show a high absorption coefficient as well as high optical conductivity. The promising linear/nonlinear optical values refer to the opportunity of utilizing the films in photovoltaic applications and/or as up-and-coming material in nonlinear devices. The (337 nm) thin film reveals an extent degree of atoms arrangement as compared to other films. Therefore, CSS2 film (337 nm) has been selected to produce the ITO/CdS/CSS2/Au heterojunction which displays a solar conversion efficiency of 1.66%.
原文链接:- NSTL
- Elsevier
Bai, JiyuanChen, MinqianZhou, ChangjieLi, Yadong...
6页查看更多>>摘要：We design an A-B interferometer with a "single quantum dot atom" embedded in the upper arm and a "double quantum dot molecule" embedded in the lower arm. The transmission coefficient and average current characteristics are studied as the time-dependent external field is introduced. When the interdot coupling strength is weak, the change of Rashba spin orbit coupling strength has a strong influence on the spin transmission coefficient. When the interdot coupling strength and Rashba spin orbit coupling strength take appropriate values, the spin up and spin down transmission coefficients completely coincide, and a resonance band emerges at the Fermi level. The spin polarization can be close to +1 or -1 by adjusting the Zeeman magnetic field, the interdot coupling strength, and the gate voltage. In the presence of photon assistance, the spin polarization changes periodically in a certain proportion, so as to realize the spin-polarized transport with controllable time-dependent external field. These findings provide a theoretical basis for the spin polarized function of A-B interferometer.
原文链接:- NSTL
- Elsevier
Bleyan, Y. Y.Hayrapetyan, D. B.
7页查看更多>>摘要：The theoretical investigation of biexciton in ellipsoidal quantum dot in the presence of the magnetic field is done in the framework of the variational method. The dependencies of the energy and the binding energy for the magnetobiexciton on the magnetic field are calculated. It is shown, that the magnetobiexciton energy increases with the increase of the magnetic field magnitude. The optical transition energy of the magnetobiexciton is calculated as a function of the magnetic field and the large semiaxis. The recombination energy, defined as a difference between the total energies of the initial and final states after recombination, is computed. The magnetization as a function of magnetic field and small semiaxis is calculated. Finally, the recombination radiative lifetime of the magnetobiexciton is estimated and shown that it is of the order of nanoseconds.
原文链接:- NSTL
- Elsevier
Ikram, AshiZulfequar, Mohammad
5页查看更多>>摘要：Present study investigates the use of visible light active green CZTS quantum dots for boosting the photo-activity of hematite thin film towards efficient hydrogen generation. A photoelectrode has been prepared by depositing a passivating layer of ZnS on Cu2ZnSnS4 (CZTS) QDs sensitized hematite thin film (H-CZTS QDs/ZnS) for solar hydrogen production. These films were implemented as photoanode in photoelectrochemical cell for photo-response measurements. XRD, HRTEM, FESEM and UV-vis diffuse reflectance spectroscopy (DRS) techniques were used to characterize these thin films for deeper analysis. The modified hematite film has showed 1.48 times more photocurrent density as compared to pristine counterpart. An increase in photocurrent could be attributed to better light absorption ability and reduced charge transfer resistance after modification. Applied bias to photon conversion efficiency was also calculated and found higher for modified sample.
原文链接:- NSTL
- Elsevier
Kaya, DoganIsik, Hasan HuseyinIsik, Ilknur BaldanAdanur, Idris...
8页查看更多>>摘要：Developing multifunctional nanoparticles (NPs) for magnetic and catalytic purposes is crucial for controlling magnetic properties and reducing production costs. We synthesized Co and low Pt loaded CoPt NPs by the modified polyol process. Co and CoPt NPs exhibited coexist fcc and hcp phases which are confirmed with x-ray diffraction and Rietveld refinement analysis. Scanning electron microscopy images revealed the average size of the NPs smaller than 9 nm with a narrow distribution. An irreversible magnetization-temperature behavior of the particles is observed in the modes of zero-field cooled and field cooled with a strong ferromagnetic signal close to 350 K. The field-dependent magnetization up to +/- 5 T was investigated to determine coercive field (H-c), exchange bias (H-E), saturation magnetization (M-s), remanent magnetization (M-r), and the ratio of remanent magnetization to saturation magnetization (M-r/M-s). There is a general decrease in magnetic values due to an increase of both the temperature and the Pt ratio in Co nanoparticles. When the Pt/Co ratio drops to 1%, the sample was measured with the highest H-c value of 648.5 Oe and M-s value of 100 emu/g at 5 K. On the contrary, increasing the concentration of Pt to 10% resulted in a reduction for the M-s value below 40 emu/g. Besides, cyclic voltammetry measurements showed apparent hydrogen reduction in the potential range of -0.91 V and -0.96 V (vs Ag/AgCl) and 10% Pt loaded CoPt NPs exhibits the highest activity after 10th cycles and increase the activity up to 15.80 mA cm(-2) at -1.2 V due to the surfactant.
原文链接:- NSTL
- Elsevier
Cai, ChunyuMa, XinjunZhao, CuilanXiao, Jinglin...
6页查看更多>>摘要：Double rings shaped quantum dot (DRSQD) is one of the important theoretical models for studying the properties of quantum dots (QD) in recent years, due to the superiority of its own double rings shaped potential (DRSP). Moreover, the influence of impurities on material properties is of great significance, because the presence of impurities can greatly affect the electro-optical properties of it. Ingeniously combining and exploring two methods of the Lee-Low-Pines unitary transformation (LLPUT) and linear combination operation (LCO) from both weak coupling limit (WCL) and strong coupling limit (SCL), the electrical properties of the fully coupled polaron (FCP) in DRSQD under the influence of impurities are indirectly considered. Under both the WCL and the SCL, the relational expressions of the polaron's vibrational frequency (VF), ground state energy (GSE) and ground state binding energy (GSBE) versus the parameters of the DRSP (PDRSP), the frequency of the DRSP (FDRSP) and the strength of the Coulomb's impurity potential (SCIP) are deduced, numerically calculated and analyzed. Besides, the contrast characteristics of the polaron's properties are given in the case of with or without impurity and under the WCL and the SCL. Simultaneously, we also compared the results of this paper with those of other literatures. The characteristic of the FCP in DRSQD under the influence of impurity effect is of great significance, because it provides new insights and references for the experimental design based on DRSQD.
原文链接:- NSTL
- Elsevier
Kwang-Hua, Chu RainerLi, Hao-ChenPolukarov, M.Ventre, C....
3页查看更多>>摘要：Recently Li et al. proposed an exactly-solvable one-dimensional quantum field theory of a dislocation for both edge as well as screw dislocations in an isotropic medium and, via the electron self-energy calculation, Li et al. claimed they can investigate directly the electron-dislocation relaxation time which is reducible to classical results obtained in [T. Ninomiya, J. Phys. Soc. Japan 25, 830 (1968)]. As the qualitative comparison is rather good thus Li et al. claimed the classical fluttering model prior to quantization has already obtained excellent agreement with experiments. However, as the present authors here point out, Ninomiya's approach and results are of doubt (violation of the principle of detailed balance; cf. V.I. Alshits and Yu. M. Sandler, Phys. Stat. Solidi (b) 64, K45 (1974) which performed the corrections: Doppler frequency shift effect included). In fact Ninomiya published a more complete paper latter on: Scr. Metal. 18, 669 (1984) which confirmed the critical remarks by Alshits and Sandier but Li et al. didn't notice or cite it. With above evidences Li et al. should seek quantitative. agreement with realistic materials so that the valid comparison with previous corrected theories considering the classical fluttering mechanism of dislocations can be confirmed.
原文链接:- NSTL
- Elsevier
Sen, SagarGupta, AjayReddy, V. R.Gupta, Ratnesh...
6页查看更多>>摘要：The training effect and the evolution of magnetic domain during the magnetization irreversible process of Fe thin film which exhibits exchange bias after F-ion implantation have been studied. Kerr microscopy measurements were carried out at different temperatures of the exchange bias F-implanted Fe thin film after the field-cooling from room temperature. With increasing anti-ferromagnetic (AFM) FeF2 layer thickness, the value of exchange bias increases and the training effect becomes weaker. Temperature-dependent study of exchange bias field indicates that with increasing F-ion fluences the disorder decreases at the Fe/FeF2 interface. Specimen of higher ion-fluence indicates a behavior that is changing from non-equilibrium state to equilibrium state and behavior of training effect is suggesting step-like.
原文链接:- NSTL
- Elsevier
Raji, P.Kumar, K. Balachandra
8页查看更多>>摘要：Calcium doped Copper ferrite (CaxCu1-xFe2O4, x = 0.0, 0.1, 0.2, 0.3) nanoparticles were prepared by co-precipitation method. The effect of calcium doping in structural, elastic and magnetic properties of copper ferrite were explored by X-ray diffraction (XRD), Scanning electron microscope (SEM), Fourier transform infrared (FTIR), and Vibrating Sample magnetometer (VSM). X-ray diffraction verified the single phase cubic spinel structure and hematite phase also present in x = 0.02 with the space group Fd3m. The average crystallite size ranged in 44-58 nm and increased with increasing Ca concentration. Scanning electron microscope images showed that the ferrite particles seem in spherical shape with agglomeration. The Fourier transform infrared spectrum showed the two main absorption bands of spinel structure in the wavenumber scale of 476-576 cm(-1) assigned to the stretching vibration of A and B sites. The three types of moduli of elasticity, Poisson's ratio, velocities of elastic waves and Debye temperature estimated using FTIR. Vibrating Sample magnetometer exhibited the room temperature ferromagnetic behavior and coercivity decreases with Ca concentration while saturation magnetization increases.
原文链接:- NSTL
- Elsevier
