Paramagnetic meissner effect in superconducting single crystals of Ba1−xKxBiO3

The paramagnetic Meissner effect (PME) in the field cooled susceptibility has been observed in superconducting single crystals of Ba1−xKxBiO3 using magnetometers of Quantum-Design Co. The PME is similar to that observed in cuprates and Nb superconductors. For the Ba0.63K0.37BiO3 crystal the PME is observed in cooling process under the field up to 750 Oe. The PME was not found in the virgin-charged superconducting magnet. The PME is found in a superconductor with trapped flux and may arise from a remnant field, a temperature inhomogeneity near Tc, and a potassium-concentration inhomogeneity.