Susceptibility measurements support high-tc superconductivity in the ba-la-cu-o system

Abstract

The magnetic susceptibility of ceramic samples in the metallic BaLaCuO system has been measured as a function of temperature. This system had earlier shown characteristic sharp drops in resistivity at low temperatures. It is found that, for small magnetic fields of less than 0.1T, the samples become diamagnetic at somewhat lower temperatures than the resistivity drop. The highest-temperature diamagnetic shift occurs at (33±2)K, and may be related to shielding currents at the onset of percolative superconductivity. The diamagnetic susceptibility can be suppressed with external fields of 1 to 5T. © 1987 IOP Publishing Ltd.