Irreversible behavior of the transport critical current in polycrystalline YBa2Cu3Oy
Abstract
Temperature and magnetic field dependence of the critical current density Jc and magnetization of the polycrystalline high Tc oxide superconductor YBa2Cu3Oy have been measured. At low temperature, Jc shows a different temperature dependence between field cooling and zero-field cooling, that is, the Jc value measured when the sample was cooled in a fixed magnetic field was larger than that measured when the sample was cooled in zero magnetic field and then a magnetic field was applied. This irreversible behavior of Jc disappeared at a reduced temperature difference 1-t proportional to H2/3 (H is the magnetic field). Moreover, we have observed that the slope dV/dJ just above Jc began to increase rapidly with increasing temperature above 70 K. These experimental results can be attributed to the effects of grain boundaries.
- Publication:
-
Applied Physics Letters
- Pub Date:
- November 1989
- DOI:
- 10.1063/1.102361
- Bibcode:
- 1989ApPhL..55.2342O
- Keywords:
-
- Crystallinity;
- High Temperature Superconductors;
- Mixed Oxides;
- Polycrystals;
- Transport Properties;
- Yttrium Oxides;
- Barium Oxides;
- Copper Oxides;
- Current Density;
- Magnetic Fields;
- Temperature Dependence;
- Volt-Ampere Characteristics;
- Solid-State Physics