Showing papers in "Physical Review in 1988"
Journal Article•
TL;DR: In this paper, the transport critical-current density in a granular superconductor in magnetic fields below about 5 x 10/sup -3/T was calculated, and it was shown that Josephson junctions are limiting transport critical current in these samples and that they lie at the grain boundaries.
Abstract: We calculate the transport critical-current density in a granular superconductor in magnetic fields below about 5 x 10/sup -3/ T. The field dependence in this region is assumed to be controlled by intragranular or intergranular Josephson junctions. Various model calculations are fitted to transport critical-current data on bulk Y/sub 1/Ba/sub 2/Cu/sub 3/O/sub 7/..sqrt../sub delta/ ceramic superconductors, whose average grain size somewhat exceeds 10 ..mu..m. The results yield an average junction cross-sectional area (thickness x length) of 4--6 ..mu..m/sup 2/. If the junctions are at the grain boundaries, a London penetration depth of about 150--300 nm is inferred, consistent with other estimates. We conclude that Josephson junctions are limiting the transport critical current in these samples and that they lie at the grain boundaries. The parameters of the fit are not consistent with Josephson junctions at twinning boundaries.
165 citations
Journal Article•
TL;DR: In this paper, the authors experimentally isolate the single and multiple-scattering terms in the X-ray-absorption fine-structure (XAFS) measurements of three compounds: GeCl, GeH, and GeHCl.
Abstract: X-ray-absorption fine-structure (XAFS) measurements of ${\\mathrm{GeCl}}_{4}$, ${\\mathrm{GeH}}_{3}$Cl, and ${\\mathrm{GeH}}_{4}$ were made. We experimentally isolate the single- and multiple-scattering terms in the XAFS of ${\\mathrm{GeCl}}_{4}$ by comparison of the spectra of the three compounds. The multiple-scattering (MS) amplitude is comparable to the single-scattering (SS) amplitude only within 15 eV of the edge. Beyond 40 eV the MS to SS amplitude ratio is less than 0.06. Calculations are in qualitative agreement with experiment. Our results suggest that XAFS data in the range 13A${\\r{}}^{\\mathrm{\\ensuremath{-}}1}$ can be analyzed in a SS picture in many cases.
11 citations
Journal Article•
TL;DR: Local environment approach for deep-level defects in semiconductors: Application to the vacancy in silicon as discussed by the authors is a local-environment approach for defect detection in semiconductor applications, which can be found in this paper.
Abstract: Local-environment approach for deep-level defects in semiconductors: Application to the vacancy in silicon
9 citations