Journal of Physics D: Applied Physics
ISSN / EISSN : 00223727 / 13616463
Current Publisher: IOP Publishing (10.1088)
Total articles ≅ 28,668
Google Scholar h5-index: 67
Latest articles in this journal
Journal of Physics D: Applied Physics; doi:10.1088/1361-6463/ab590d
Abstract:We investigate how epitaxial strain affects the conductivity and charge transport of Ba0.6La0.4TiO3 (BLTO) films deposited by pulsed laser deposition. Depositing BLTO films with thicknesses varying from 14.1 to 95.9 nm gives differing epitaxial strains, with a maximum strain up to ~6% for the thinnest film of 14.1 nm. Transport measurements demonstrate that film thickness (i.e., epitaxial strain) affects the conductivity, carrier mobility, and concentration. Measurements of resistivity versus temperature demonstrate that all the BLTO films undergo a distinct semiconductor-metal phase transition, and the transition temperature TSM also depends clearly on strain. For all the films, the charge transport follows the small-polaron hopping mechanism below TSM and the thermal phonon scattering mechanism above TSM. These results prove that strain in epitaxial films strongly affects the conductivity and charge transport of traditional insulating ferroelectric oxide films.
Journal of Physics D: Applied Physics; doi:10.1088/1361-6463/ab5908
Abstract:In this work, a sulfur and nitrogen co-doping technique has been demonstrated for the diamond epilayer growth by microwave plasma chemical vapor deposition (MPCVD). Results show that the nitrogen concentration in films could be tailored by co-doping of sulfur. At a certain growth condition, single nitrogen-vacancy (NV) colour centers could be achieved. A competition mechanism between sulfur and nitrogen incorporation in the H2/CH4 plasma is proposed to explain the efficient suppression of the incorporated nitrogen. Briefly, adding H2S decreases the growth rate and the resulting (S or S2) species could react with the dissociated nitrogen atoms to form S and N-containing clusters. Hence, the concentration of the NV centers in diamond is decreased. Meanwhile, density functional theory (DFT) calculations indicate an increment of the nitrogen-vacancy formation energy in the presence of sulfur, which confirms that sulfur has a suppression effect on the formation of the NV centers. This study provides a new method to adjust the concentration of the NV centers in the diamond films.
Journal of Physics D: Applied Physics; doi:10.1088/1361-6463/ab590e
Abstract:In this work we regulate the crystal structure of Cu3SbSe4 through alloying Cu3SnS4, and decouple the contribution of the phonon scattering on the distorted crystal structure. This contribution, which was not paid much attention to in the Cu3SbSe4-based systems previously, leads to 44% (RT) and 22% (607 K) drop in the lattice part (κL). Therefore, it is of great importance to improve the thermoelectric performance. At the same time, we regulate the carrier concentration (nH) through co-alloying Cu3SnS4 and ZnSe and attain the optimal nH value (~1020 cm-3) at RT. As a result, the electrical property improves with the highest power factor (PF) of 12.63 μWcm-1K-2 for the solid solution (Cu3SbSe4)0.1(Cu3SnS4)0.9(ZnSe)0.02. Consequently, the thermoelectric performance improves remarkably with the peak ZT value of 0.65 at 700 K while that of the pristine Cu3SbSe4 is only 0.26 at 588 K.
Journal of Physics D: Applied Physics; doi:10.1088/1361-6463/ab58ec
Abstract:We analyzed the third harmonic generation (THG) of 1064 nm, 28 ps radiation in the candle and ethanol flames. The formation of soot nanoparticles in the candle flame led to the increase of third harmonic yield compared to the ethanol flame. 12- and 24-fold enhancement of the third harmonic yield in candle and ethanol flames compared to the third harmonic generation in air was achieved. The influence of the nonlinear refraction in air and combustion flames on the phase-matching conditions of THG was found responsible for deviation from the cubic I3 (I) dependence. THG conversion efficiencies of Nd:YAG laser radiation were found to be 110-5, 1.210-4 and 2.410-4 in the cases of air, carbon flame and ethanol flame media, respectively. Furthermore, the super-hydrophobic properties of the deposited carbon species from the candle flame were demonstrated.
Journal of Physics D: Applied Physics; doi:10.1088/1361-6463/ab586f
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Journal of Physics D: Applied Physics; doi:10.1088/1361-6463/ab5878
Abstract:We present a high-efficiency Fresnel lens based on the theory of extraordinary acoustic transmission of plate-wave resonance. We studied, experimentally and numerically, the acoustic pressure gain of the Fresnel lens with and without gratings on the back. We found that the transmission coefficient of the incident acoustic waves through the lens with gratings on the back was much higher than that of the lens without gratings, thus increasing the acoustic pressure gain at the focal point of an impedance-mismatched Fresnel lens by 14.1 dB. We then optimized the grating width in the structure, thereby increasing the acoustic pressure gain by 16.3 dB. This lens has potential applications in acoustic imaging and medical diagnosis.
Journal of Physics D: Applied Physics; doi:10.1088/1361-6463/ab5873
Abstract:Herein, a simple and facile two-step sonication method was developed for the preparation of nanosheets-like MoS2 wrapped graphene nanohybrids for energy storage and hydrogen evolution reactions applications. TEM and HR-TEM image raveled that the 120 nm sized lateral diameter of sheet-like MoS2 was completely immobilized on the surfaces of graphene via probe sonication method. The resultant nanohybrid exhibited bifunctional activities of supercapacitor and HER. With this tailored bifunctional nanoarchitecture, the nanohybrid based electrode showed an improved specific capacitance of 350 F/g for a current load of 1 A/g with a cyclic efficiency of 85 % in 6 M KOH electrolyte solution. Additionally, the developed MG11 nanohybrid was tested as an electrocatalyst for hydrogen evolution reaction (HER). The latter exhibited a low onset potential of ~ 125 mV with a Tafel slope of 41 mV/decade. Thus, MG11 nanohybrid presents an excellent prospect for a low-cost electrode for supercapacitor and an electrocatalyst for hydrogen evolution reaction.
Journal of Physics D: Applied Physics; doi:10.1088/1361-6463/ab5883
Abstract:The resistive switching (RS) of Au/BiFeO3/SrRuO3 samples was shown to be controllable by using a thermal treatment and an electrical stressing method. Such a modulation of resistive switching effect can be associated to the oxygen vacancy movement and redistribution within the BiFeO3 thin film and the trapping/detrapping of charge carriers at the interfaces. After the application of a negative voltage to the thin film for a stressing period, a resistive switching reversal effect occurred and the current retention ability in the low resistance state increased, indicating an increase in the trap density at the interface and an enhancement of the charge carrier trapping ability. The trap density, trap level, and Schottky barrier height all display corresponding trends in their values as a result of the modulation of RS effect. The results indicate that the greater the accumulation of oxygen vacancies at any the film/electrode interface, when a reverse bias is applied the higher the resistance ratio was under reverse bias. Its diffusion process was likely to be hindered and the trapped charge carriers could be retained after a long time of electrical stressing.
Journal of Physics D: Applied Physics; doi:10.1088/1361-6463/ab58b6
Journal of Physics D: Applied Physics; doi:10.1088/1361-6463/ab58b4