Multi-field electron emission pattern of 2D emitter: Illustrated with graphene
The mechanism of laser-assisted multi-field electron emission of two-dimensional emitters is investigated theoretically. The process is basically a coldfield electron emission but having morecontrollable components: a uniformelectric fieldcontrols the emission potential barrier, amagnetic fieldcontrols the quantum states of the emitter, while an optical fieldcontrols electron populations of specified quantum states. It provides a highly orientational vacuum electron line source whose divergence angle over the beam plane is inversely proportional to square root of the emitter height. Calculations are carried out forgraphene...
Source: Journal of Applied Physics - November 29, 2016 Category: Physics Authors: Ma Luo and Zhibing Li Source Type: research
A perovskite lead-free antiferroelectric xCaHfO3-(1-x) NaNbO3 with induced double hysteresis loops at room temperature
We demonstrated a new CaHfO3-NaNbO3 solid solution system that allows stable antiferroelectric (AFE) (P) phase to exist under ambient conditions. Based on crystal chemistry viewpoint of relative change of the Goldschmidt tolerance factor (t) and polarizability, two new solid solutions were fabricated using theperovskite end member CaHfO3. It was found that the CaHfO3 effectively stabilized the antiferroelectric (AFE) P phase in NaNbO3. In this article, electrical properties and transmission electron microscopy experiments were conducted to verify the stabilization and enhancement of antiferroelectric behavior over the vari...
Source: Journal of Applied Physics - November 29, 2016 Category: Physics Authors: Lisheng Gao, Hanzheng Guo, Shujun Zhang and Clive A. Randall Source Type: research
Current-controlled unidirectional edge-meron motion
In order to address many of the challenges and bottlenecks currently experienced by traditionalcharge-based technologies, various alternatives are being actively explored to provide potential solutions of device miniaturization and scaling in the post-Moore's-law era. Amongst these alternatives, spintronic physics and devices have recently attracted rapidly increasing interest by exploiting the additional degree of electrons-spin. For example, magnetic domain-wall racetrack-memory and logic devices have been realized via manipulating domain-wall motion. As compared to domain-wall-based devices, magneticskyrmions have the a...
Source: Journal of Applied Physics - November 29, 2016 Category: Physics Authors: Xiangjun Xing, Philip W. T. Pong and Yan Zhou Source Type: research
Effects of nonthermal plasma jet irradiation on the selective production of H2O2 and NO2 − in liquid water
We present the effects of the application of a nonthermalplasma jet to aliquid surface on H2O2 and NO2− generation in the liquid. Two distinctplasma irradiation conditions, withplasma contact and with no observableplasma contact with theliquid surface, were precisely compared. When theplasma was made to touch theliquid surface, the H2O2 concentration of the plasma-treatedwater was much higher than the NO2− concentration. In contrast, when no observable contact of theplasma with theliquid surface occurred, the ratio of the NO2− to H2O2 concentration became over 1 and NO2− became more dominant than H2O2 in the plasma...
Source: Journal of Applied Physics - November 29, 2016 Category: Physics Authors: Giichiro Uchida, Atsushi Nakajima, Taiki Ito, Kosuke Takenaka, Toshiyuki Kawasaki, Kazunori Koga, Masaharu Shiratani and Yuichi Setsuhara Source Type: research
Structural, electrical, and optical characterization of as grown and oxidized zinc nitride thin films
Zinc Nitride(Zn3N2) films weregrown by DC sputtering of aZn target in a N2 plasma under a variety of differentgrowth conditions, which resulted in the deposition of films with variable compositions. The as deposited films exhibited a polycrystallineZn3N2 structure, which was converted to a ZnO-based structure after several weeks of ambient exposure.Zn3N2 films that were N-poor exhibited electrical properties indicative of a natively doped semiconductor and reached a minimumcarrier concentration in the order of 1018 cm−3 at compositions, which approached the stoichiometric ratio ofZn3N2. A maximumcarrier mobility of 33...
Source: Journal of Applied Physics - November 28, 2016 Category: Physics Authors: A. Trapalis, J. Heffernan, I. Farrer, J. Sharman and A. Kean Source Type: research
Band offset in (Ga, In)As/Ga(As, Sb) heterostructures
A series of (Ga, In)As/GaAs/Ga(As, Sb) multi-quantum wellheterostructures is analyzed using temperature- and power-dependentphotoluminescence(PL) spectroscopy. PronouncedPL variations with sample temperature are observed and analyzed using microscopic many-body theory andband structure calculations based on the k ⋅p method. This theory-experiment comparison reveals an unusual, temperature dependent variation of the band alignment between the (Ga, In)As and Ga(As, Sb)quantum wells. (Source: Journal of Applied Physics)
Source: Journal of Applied Physics - November 28, 2016 Category: Physics Authors: S. Gies, M. J. Weseloh, C. Fuchs, W. Stolz, J. Hader, J. V. Moloney, S. W. Koch and W. Heimbrodt Source Type: research
Structural investigation of SiSn/(reduced graphene oxide) nanocomposite powder for Li-ion battery anode applications
We synthesized SiSn/(reducedgraphene oxide (rGO))nanocompositepowder for a Li-ion battery material and characterized the structure bytransmission electron microscopy(TEM) and analytical scanningtransmission electron microscopy (STEM).Graphene oxide was prepared by Hummers method. Thegraphene oxidepowder processed by heat treatment was added together with Sipowder into a solution of SnCl2⋅ 2(H2O) dissolved in N2 bubbled ethylene glycol, and the solution was reacted with NaBH4. The product had a nominal atomic ratio of Si: Sn: C = 14: 3.5: 100. High-resolution TEM/STEManalysis revealed that thepowder consisted of crys...
Source: Journal of Applied Physics - November 28, 2016 Category: Physics Authors: Masahiro Kawasaki, Viratchara Laokawee, Thapanee Sarakonsri, Takashi Hashizume and Makoto Shiojiri Source Type: research
Voltage-controlled magnetization switching in MRAMs in conjunction with spin-transfer torque and applied magnetic field
Voltage-controlledmagnetic anisotropy (VCMA) effect has attracted a significant amount of attention in recent years because of its low cellpower consumption during theanisotropy modulation of a thin ferromagnetic film. However, the applied voltage orelectric field alone is not enough to completely and reliably reverse the magnetization of the free layer of a magnetic random access memory (MRAM) cell from anti-parallel to parallel configuration or vice versa. An additional symmetry-breaking mechanism needs to be employed to ensure the deterministic writing process. Combinations of voltage-controlledmagnetic anisotropy toget...
Source: Journal of Applied Physics - November 28, 2016 Category: Physics Authors: Kamaram Munira, Sumeet C. Pandey, Witold Kula and Gurtej S. Sandhu Source Type: research
Numerical model for electrical explosion of copper wires in water
This paper presents a simple but quite accurate numericalmodel for analyzing electricalexplosion ofcopperwires in water. The numericalmodel solves a circuit equation coupled with one-dimensional magneto-hydrodynamic (MHD) equations with the help of appropriate wide-rangeequation of state(EOS) andelectrical conductivity forcopper. The MHD equations are formulated in a Lagrangian form to identify the interface between thewire and surrounding water clearly. A quotidianEOS (QEOS) that is known as the simplest form ofEOS is utilized to build wide-rangeEOS forcopper. In the QEOS, we consider theliquid-vapor phase transition, whi...
Source: Journal of Applied Physics - November 28, 2016 Category: Physics Authors: Kyoung-Jae Chung, Kern Lee, Y. S. Hwang and Deok-Kyu Kim Source Type: research
Publisher's Note: “Dependence of grain size and defect density on the magnetic properties of mechanically alloyed Fe90W10 powder” [J. Appl. Phys. 120, 143903 (2016)]
(Source: Journal of Applied Physics)
Source: Journal of Applied Physics - November 23, 2016 Category: Physics Authors: N. K. Yamoah, M. A. Koten, D. Thompson, C. Nannuri, J. Narayan, J. E. Shield and D. Kumar Source Type: research
Edge-state-induced energy splitting of exciton triplet states in graphene nanoflakes
We explore the edge-state-induced exciton effects ingraphene nanoflakes with various edges and shapes. Theenergy degeneracy of the three triplet excitons is preserved in hexagonal armchair-edgedgraphene nanoflakes and triangle armchair-edgedgraphene nanoflakes. However, thisenergy degeneracy is partly broken in hexagonal zigzag-edgedgraphene nanoflakes, because of the zigzag-edge-induced spinpolarization and the antiferromagnetic coupling between nearest-neighboring edges. And the degeneracy is totally broken in triangle zigzag-edgedgraphene nanoflakes, due to the spin-polarized edge states and the ferromagnetic coupling b...
Source: Journal of Applied Physics - November 23, 2016 Category: Physics Authors: Yan Lu, Sheng Wei, Jing Jin, Wengang Lu and Li Wang Source Type: research
Large electrostrictive effect in (Ba1-xGd2x/3)Zr0.3Ti0.7O3 relaxor towards moderate field actuator and energy storage applications
The need of lead-free high performanceceramics with large electrostrictive effect, minimumhysteresis loss andenergy storage ability at room temperature has become indispensable. At room temperature one of the key challenges inceramicmaterials is to enhance the electrostrictive andenergy storageproperties simultaneously. In this regards, lead-free gadolinium modified barium zirconate titanate (Ba1-xGd2x/3)(Zr0.3Ti0.7)O3 (x = 0.02, 0.04, 0.06, 0.08, 0.10)ceramic was experimentally investigated to gain the competent electromechanical parameters near room temperature. Dielectric measurements exhibit a diffuse type ofphase...
Source: Journal of Applied Physics - November 23, 2016 Category: Physics Authors: S. K. Ghosh, Sujoy Saha, T. P. Sinha and S. K. Rout Source Type: research
Effect of germanium doping on electrical properties of n-type 4H-SiC homoepitaxial layers grown by chemical vapor deposition
The effect ofgermanium(Ge) on n-type 4H-SiC is experimentally studied by electrical characterization ofhomoepitaxial layersgrown bychemical vapor deposition(CVD). Measurements show thatelectrical properties ofepitaxial layers can be changed by intentional incorporation of germane (GeH4) gas during the deposition process. On the nanoscale, two-dimensional mappings acquired with conductive atomic force microscopy show preferential conductive paths on the surface of Ge-doped samples, which are related to the presence of this isoelectronic impurity. Hall effect measurements confirm that also macroscopicelectrical properties of...
Source: Journal of Applied Physics - November 22, 2016 Category: Physics Authors: T. Sledziewski, M. Vivona, K. Alassaad, P. Kwasnicki, R. Arvinte, S. Beljakowa, H. B. Weber, F. Giannazzo, H. Peyre, V. Souliere, T. Chassagne, M. Zielinski, S. Juillaguet, G. Ferro, F. Roccaforte and M. Krieger Source Type: research
Elemental redistributions at structural defects in Cu(In,Ga)Se2 thin films for solar cells
The microstructural evolution of Cu(In,Ga)Se2 absorber layers during a three-stage-type co-evaporation process was studied to elucidate the effect of a Cu-rich stage on the formation of extended structural defects. Defect densities for two Cu-poor samples, one interrupted before and one after this crucial Cu-rich composition stage, were investigated by scanning transmission electron microscopy(STEM) imaging. The structure and chemical nature of individual defects were investigated by aberration-corrected high-resolutionSTEM in combination withelectron energy-loss spectroscopy on the atomic-scale. In spite of the different ...
Source: Journal of Applied Physics - November 22, 2016 Category: Physics Authors: E. Simsek Sanli, Q. M. Ramasse, W. Sigle, D. Abou-Ras, R. Mainz, A. Weber, H.-J. Kleebe and P. A. van Aken Source Type: research
Negative thermal expansion and photoluminescence properties in a novel material ZrScW2PO12
A novelmaterial, ZrScW2PO12, with negativethermal expansion (NTE) behavior, at least from 138 to 1300 K, and intensephotoluminescence(PL)property is first reported in this paper.Temperature dependent Raman andPLspectral studies indicate that thematerial holds an orthorhombicstructure down to about 74 K and exhibits NTEproperty in thetemperature range. The intensePL covering nearly the whole visible region was observed and can be deconvoluted into four bands, which present different shifts with elevation oftemperature. The abundant opticalproperty may be attributed to n- and p-type like co-doping effect and the specif...
Source: Journal of Applied Physics - November 22, 2016 Category: Physics Authors: Xianghong Ge, Xiansheng Liu, Yongguang Cheng, Baohe Yuan, Dongxia Chen, Mingju Chao, Juan Guo, Junqiao Wang and Erjun Liang Source Type: research
