• AIP Publishing
• AVS: Science & Technology of Materials, Interfaces, and Processing
• Acoustical Society of America
• American Association of Physicists in Medicine
• American Association of Physics Teachers
• American Crystallographic Association, Inc.
• Chinese Physical Society
• Chinese Society of Theoretical and Applied Mechanics
• Laser Institute of America
• The Society of Rheology

Journal of Applied Physics is an influential international journal publishing significant new experimental and theoretical results of applied physics research. Topics covered in Journal of Applied Physics are diverse, reflecting the most current applied physics research, and include areas of particular emerging interest. Content is published online daily and collected into weekly online and printed issues (48 issues per year).

Journal of Applied Physics: New Article Acceptance Criteria

Editor's Picks

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  Direct numerical simulation of shear localization and decomposition reactions in shock-loaded HMX crystal

  dx.doi.org/10.1063/1.4918538

  A numerical model is developed to study the shock wave ignition of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) crystal. The model accounts for the coupling between crystal thermal/mechanical responses and chemical reactions that are driven by the temperature field. This allows for the direct numerical simulation of decomposition reactions in the hot spots formed by mechanical loading. The model is used to simulate intragranular pore collapse under shock wave loading. In a reference case: (i) shear-enabled micro-jetting is responsible for a modest extent of reaction in the pore collapse region, and (ii) shear banding is found to be an important mode of localization. The shear bands, which are filled with molten HMX, grow out of the pore collapse region and serve as potential ignition sites. The model predictions of shear banding and reactivity are found to be quite sensitive to the respective flow strengths of the solid and liquid phases. In this regard, it is shown that reasonable assumptions of liquid-HMX viscosity can lead to chemical reactions within the shear bands on a nanosecond time scale.

• 1/2Na_1/2TiO₃–xBaTiO₃ single crystals across the morphotropic phase boundary" title="Anisotropy of ferroelectric behavior of (1 − x)Bi_1/2Na_1/2TiO₃–xBaTiO₃ single crystals across the morphotropic phase boundary" />

  Anisotropy of ferroelectric behavior of (1 − x)Bi_1/2Na_1/2TiO₃–xBaTiO₃ single crystals across the morphotropic phase boundary

  dx.doi.org/10.1063/1.4891529

  (1 − x)(Bi1/2Na1/2)TiO3-xBaTiO3 (BNT-100xBT) single crystals with three different compositions of x = 0.036, 0.065, and 0.088, covering the rhombohedral to predominantly tetragonal region of the phase diagram and encompassing the morphotropic phase boundary (MPB), were grown by top-seeded solution growth. Dielectric and ferroelectric measurements were performed on samples with different orientations with respect to the crystallographic axes. While the results complied with the current understanding of the crystallographic structure, no enhancement of electromechanical properties based on transient polarization rotation was observed. This clearly sets BNT-100xBT apart from other relaxor ferroelectric systems with a rhombohedral-tetragonal MPB such as (1 − x) Pb(Mg1/3Nb2/3)O3-xPbTiO3. An anomaly was observed in the poling behavior of the strain in 〈001〉 oriented BNT-100xBT in the immediate vicinity of the MPB with x = 0.065, resulting in a giant small-signal piezoelectric coefficient d 33 of 4600 pm/V. This effect is hypothesized to be due to an irreversible phase change from rhombohedral polar nanoregions to tetragonal ferroelectric microdomains.

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  Large area photodetector based on microwave cavity perturbation techniques

  dx.doi.org/10.1063/1.4891518

  We present a preliminary study to develop a large area photodetector, based on a semiconductor crystal placed inside a superconducting resonant cavity. Laser pulses are detected through a variation of the cavity impedance, as a consequence of the conductivity change in the semiconductor. A novel method, whereby the designed photodetector is simulated by finite element analysis, makes it possible to perform pulse-height spectroscopy on the reflected microwave signals. We measure an energy sensitivity of 100 fJ in the average mode without the employment of low noise electronics and suggest possible ways to further reduce the single-shot detection threshold, based on the results of the described method.

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  Charging of moving surfaces by corona discharges sustained in air

  dx.doi.org/10.1063/1.4890520

  Atmospheric pressure corona discharges are used in electrophotographic (EP) printing technologies for charging imaging surfaces such as photoconductors. A typical corona discharge consists of a wire (or wire array) biased with a few hundred volts of dc plus a few kV of ac voltage. An electric discharge is produced around the corona wire from which electrons drift towards and charge the underlying dielectric surface. The surface charging reduces the voltage drop across the gap between the corona wire and the dielectric surface, which then terminates the discharge, as in a dielectric barrier discharge. In printing applications, this underlying surface is continuously moving throughout the charging process. For example, previously charged surfaces, which had reduced the local electric field and terminated the local discharge, are translated out of the field of view and are replaced with uncharged surface. The uncharged surface produces a rebound in the electric field in the vicinity of the corona wire which in turn results in re-ignition of the discharge. The discharge, so reignited, is then asymmetric. We found that in the idealized corona charging system we investigated, a negatively dc biased corona blade with a dielectric covered ground electrode, the discharge is initially sustained by electron impact ionization from the bulk plasma and then dominated by ionization from sheath accelerated secondary electrons. Depending on the speed of the underlying surface, the periodic re-ignition of the discharge can produce an oscillatory charging pattern on the moving surface.

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  Dynamic density field measurements of an explosively driven phase transition in iron

  dx.doi.org/10.1063/1.4890509

  We provide a unique set of observations of the behavior of the phase transition under a complex axially symmetric loading path created by sweeping a detonation wave along the end surface of a cylindrical sample. The primary data sets are the measured mass density distributions acquired at 5 independent times during the sweep of the detonation along the surface. Shocked regions and boundaries are measured, as well as regions and boundaries of elevated density (presumed to be the phase iron). The formation and dynamics of these regions were captured and are available for comparisons to material descriptions. We also applied 16 Photon Doppler Velocimetry probes to capture the free surface velocity along a discrete set of radially distributed points in order to compare and correlate the density measurements with previous shock wave studies. The velocimetry data are in nearly exact agreement with previous shock wave studies of the phase transition, the density distributions, while generally in agreement with expectations evolved from the shock wave studies, show that the epsilon phase is generated in regions of high shear stress but at hydrostatic stresses below the typically quoted 13 GPa value. The density field measurements are particularly useful for observing the effects of the forward and reverse transformation kinetics, as well as the reverse transformation hysteresis.