Journal of Applied Physics

Electrochemical energization of n-GaN was conducted under reverse-bias conditions as well as forward-bias conditions that were used in our previous studies for anodization, and electrical properties of energized n-GaN were examined. The surface composition and electrical properties of the energized n-GaN were evaluated by x-ray photoelectron spectroscopy (XPS) and temperature-dependent Hall-effec…

Dislocation loops are typical irradiation defects that significantly influence the mechanical behavior of irradiated materials. In this work, molecular dynamics simulations are performed to investigate the influence mechanisms of dislocation loops on damage evolution of single crystal copper, with a focus on the effects of loading conditions (uniaxial and triaxial strain tension) and dislocation …

Plastic-bonded explosives (PBXs) are pressed composites of energetic crystals (>90 wt. %), polymeric binder, and an internal porosity structure (1–2 vol. %). The binder ensures material stability, while porosity promotes more reliable reaction initiation. These microstructural features critically influence the bulk mechanical and detonation performance properties of the high explosive (HE)…

Field emitters are one of the promising electron sources for vacuum electronic devices operating in mm-wave and terahertz frequencies, where emission performance is critically governed by the field enhancement factor. While extensive analytical models exist for one-dimensional emitters like carbon nanotubes and Spindt tip, the corresponding framework for a thin-film (like two-dimensional) emitter…

Conventional acoustic metasurfaces have shown exceptional capability through spatial wavefront engineering, but the degrees of freedom in the wavevector domain remain to be unlocked. Here, we shift the manipulation paradigm from the spatial domain to the wavevector domain via nonlocal metasurfaces (NMSs). The proposed NMS consists of two sublayers of surface groove structures cascaded via a nonlo…

We recently found that the electromagnetic scattering problem can be solved efficiently using an approach that expresses the fields in terms of a set of orthonormal basis functions. In this paper, we apply computational conformal geometry with the conformal energy minimization (CEM) algorithm to make possible fast solution of finite-frequency electromagnetic problems involving arbitrarily shaped,…

We report the angle-dependent magnetoresistances (MRs) of platinum diselenide (PtSe2) in the Dirac semimetal phase. The negative longitudinal MR observed in parallel fields persists up to ∼50 K, which is quantitatively consistent with the chiral anomaly of Dirac fermions. When the field is perpendicular to the current, a low-field transition from positive to negative transverse MR is observed bet…

Maintaining stable absorption performance at large oblique incidence while achieving broadband sound absorption remains a major challenge for conventional sound-absorbing materials. To address this issue, a sector-shaped acoustic metamaterial composed of two-dimensional gradient waveguides and a porous backing cavity is proposed to achieve broadband and wide-angle sound absorption. By arranging t…

Germanium lead (GePb) alloys have shown promising potential as a material platform for fabricating mid-infrared photodetectors, where the Pb content enables tuning of the bandgap. However, fabricating such devices using GePb is challenging because the equilibrium solid solubility of Pb in Ge is in the parts per million range. Here, we synthesize the metastable GePb alloy by Pb implantation into G…

A two-dimensional axisymmetric direct-implicit particle-in-cell/Monte Carlo collision model is used to study pressure-dependent electron heating and discharge localization in an electronegative CF4 plasma sustained by an inductive source with RF substrate bias. Under fixed absorbed inductive and bias powers, increasing the pressure from 20 to 200 mTorr transforms the discharge from a relatively d…

It is well known that Eringen’s nonlocal thermoelasticity theory using the nonlocal Fourier law of heat conduction and its modifications has been widely applied to harmonic plane wave problems. However, it has recently been proven that a significant class of these problems such as Rayleigh wave propagation in layered nonlocal thermoelastic half-spaces is ill-posed under this theory in the sense o…

The cycle endurance characteristics of HfO2-based ferroelectric (FE-HfO2) capacitors were systematically investigated in terms of area, temperature, film thickness, and ferroelectric polarization. Cycle endurance exhibited distinct electric-field dependent behavior, which is classified into low, middle, and high field regimes. For area, the electric-field dependence does not change with area. The…

Drop impact is a classical problem in fluid mechanics, yet its implications for biological systems remain largely unexplored. Upon impact, droplets generate transient interfacial force fields composed of localized pressure, shear, and extensional stresses that evolve over microsecond-to-millisecond timescales. In complex biofluids and at soft interfaces, these stresses are not simply dissipated, …

Non-Hermitian topological superconductors provide a setting in which point-gap topology, non-Hermitian skin effects, and Majorana zero modes are strongly intertwined. In this work, we adopt a coefficient-based approach for computing winding numbers and deriving analytical expressions for phase boundaries in one-dimensional non-Hermitian topological superconductors characterized by point-gap topol…

Quantitative interpretation of thickness-dependent spintronic/orbitronic terahertz (THz) emitter (STE/OTE) experiments requires reliable knowledge of how pump energy is distributed among individual layers. However, this distribution is often approximated using tabulated optical constants or simple thickness-weighted estimation, which may not represent actual thin-film spectral parameters. Here, w…

Amorphous metal oxide interlayers are widely used to stabilize Li+ transport at battery interfaces, yet the underlying transport mechanisms remain unclear. Here, Li+ transport in amorphous TiOx (a-TiOx) thin films prepared by mist chemical vapor deposition was investigated by comparing electrochemical lithiation with concentration-driven Li+ insertion induced by LiPF6 exposure. Electrochemical li…

This study reports the discovery and characterization of a previously unknown intermetallic compound phase, Cu20Bi9, within Cu75Sn13Bi12 alloy solidified both onboard China’s Space Station and under ground-based conditions. Combined with selected-area electron diffraction (SAED), atomic-resolution high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), and energy-dis…

We develop a sub-lattice phase-field model of Hf1−xZrxO2 incorporating zirconium (Zr) concentration (x)-dependence. Our framework expands the time-dependent Ginzburg–Landau equation to the sub-lattice level and incorporates x-dependent interaction parameters and gradient coefficients. Our experimentally calibrated model captures the evolution of charge–voltage (Q–V) characteristics for x ranging …

In this article, on an example of modeling the equilibrium state of crystalline copper, the possibility of predicting the atomic configuration at the next time step using data on atomic configurations at several previous time steps by a bidirectional recurrent neural network trained on classical molecular dynamics data is shown. A network with a minimum number of hidden layers (the number of laye…

Efficient spin–orbit torque (SOT) switching of perpendicular magnetization is of crucial importance for the magnetic random-access memory. In this work, we study the ultrafast switching of a perpendicular ferrimagnetic alloy by the SOT and an external field (Hx) along the current direction. We find that the magnetization reversal occurs first at the corner of the sample and then propagates to the…