Magnetic susceptibility of rapidly solidified YBa2Cu3O7−x superconductors

Abstract
The superconducting YBa2Cu3O7−x phase has been produced through a novel rapid solidification processing route yielding a high‐quality granular superconducting phase. Features in the magnetic susceptibility as measured at various fields can be attributed to important transitions in the superconducting behavior of these materials. At low fields (∼20 Oe) anomalies in the susceptibility arise from decoupling of the grains in these polycrystalline materials. Susceptibility response at higher fields (∼100 Oe) is representative of randomly oriented superconducting grains which show local superconducting current densities comparable to those of single crystals. At even higher fields features consistent with Muller’s superconducting glass state model are observed.