Transport and magnetization measurements of the high-T_c superconductor Ba_1-xK_xBiO₃

The perovskite Ba_1-xK_xBiO₃ (BKBO) exhibits several interesting properties, including charge-density wave order accompanied by oxygen-breathing structural distortions and a high superconducting transition temperature (T_c) of just above 30 K [1]. There has been considerable recent progress toward understanding the structural properties of BKBO [2], yet electronic transport measurements have historically been difficult due to poor surface quality and large contact resistance. Our recent seeded growths have successfully produced sizable homogeneous crystals, allowing for better electrical contacts with sample surfaces. Here we present Hall effect and magnetoresistance measurements of BKBO crystals at several potassium concentrations. We also utilize a contactless probe to measure higher-order nonlinear magnetization [3], allowing us to sensitively probe superconducting fluctuations.

[1] A. W. Sleight, Physica C 514, 152 (2015)



[2] S. Griffitt, M. Spaić et al., Nat. Commun. 14, 845 (2023)



[3] D. Pelc et al. Nat. Comm. 10, 2729 (2019)