arXiv subjects

B. Zeimetz

Publications and source records attributed to B. Zeimetz.

2 recordsLinked to original sources

arXiv2002

Application of Percolation Theory to Current Transfer in Granular Superconductors

We investigate the description of current transfer in polycrystalline superconductors by percolation theory and its limitations. Various computer models that have been proposed are reviewed and related to the experimental and theoretical framework. While some conductor properties can be well described by percolation theory and models, we argue that a conceptual gap exists between experiment and theory. This gap has to be bridged by finding relations between electromagnetic and statistical parameters. We derive various such relations and compare them with recent simulation data. In particular, we suggest a new scaling law between the two fundamental variables current and probability.

cond-mat.supr-con↗

arXiv2001

Superconducting properties of the powder-in-tube Cu-Mg-B and Ag-Mg-B wires

The new class of Mg-B superconducting conductors was prepared using the standard in-situ powder-in-tube, PIT, method where Mg+2B mixture was used to fill the copper and silver tubes. Study of the intergranular current, grain connectivity and superconducting phases in wires were conducted by AC susceptibility measurements and direct four point transport measurements. Using SQUID magnetometer, magnetisation versus magnetic field (M-H) curves of the round wires after reactive diffusion were measured at temperatures 5K and magnetic field up to 5T to define the Jcmag . The direct current density measurements of the in-situ Cu-MgB2 performed at 4.2K gave the value of 10^9 Am-2 .

cond-mat.supr-con↗