Intergranular bondings in YBa<sub>2</sub>Cu<sub>3</sub>O<sub>7-x</sub> ceramics and their character versus sample density
G V Golubnichaja; A Ya Kirichenko; N T Cherpak; G V Golubnichaja; Inst. of Radiophys. & Electron., Acad. of Sci., Kharkov, Ukrainian SSR, USSR; A Ya Kirichenko; Inst. of Radiophys. & Electron., Acad. of Sci., Kharkov, Ukrainian SSR, USSR; N T Cherpak; Inst. of Radiophys. & Electron., Acad. of Sci., Kharkov, Ukrainian SSR, USSR
Журнал:
Superconductor Science and Technology
Дата:
1991-01-01
Аннотация:
The dependence of the radiofrequency energy absorption Q<sup>-1</sup> (f=2-5 MHz) upon temperature, density and static magnetic field H has been studied for samples of hot-pressed YBCO ceramics. The experimental data suggests that in the ceramics with gamma >5 g/cm most intergranular bondings are in the form of Josephson bridges. Lowering of the ceramics density results firstly in a narrowing of the bridges' widths followed by a breakdown and gradual transition to SIS type bondings and from them to the percolation threshold.
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