Paramagnetic Meissner Effect in Superconducting Single Crystals of Ba_{1-x}K_xBiO_3

TL;DR

This study reports the observation of the paramagnetic Meissner effect in Ba_{1-x}K_xBiO_3 single crystals, highlighting its similarity to effects in cuprates and Nb superconductors and exploring its possible origins.

Contribution

First observation of PME in Ba_{1-x}K_xBiO_3 crystals, expanding understanding of magnetic phenomena in this superconductor family.

Findings

PME observed in Ba_{0.63}K_{0.37}BiO_3 under fields up to 750 Oe

PME linked to trapped flux, remnant fields, and inhomogeneities

No PME detected in virgin-charged superconducting magnet

Abstract

The paramagnetic Meissner effect (PME) in the field cooled susceptibility has been observed in superconducting single crystals of Ba_{1-x}K_xBiO_3 using magnetometers of Quantum-Design Co.. The PME is similar to that observed in cuprates and Nb superconductors. For the Ba_{0.63}K_{0.37}BiO_3 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 T_c, and a potassium-concentration inhomogeneity.