Origin of the varying temperature dependence of metallic BKBO conductivity

Determine whether the differing temperature dependences of electrical conductivity reported for metallic Ba_{1-x}K_xBiO_3 arise from variations in crystal quality or from material inhomogeneities.

Background

Metallic Ba_{1-x}K_xBiO_3 exhibits strongly varying reported temperature dependences of conductivity, ranging from metallic behavior to pseudogap-like behavior and changes in slope with temperature. The paper identifies crystal quality and inhomogeneity as possible explanations for these discrepancies, with related reports suggesting coexistence of metallic and insulating phases or nonuniform potassium distribution.

Resolving the origin of the transport variation is important for interpreting the electronic properties of Ba_{1-x}K_xBiO_3 and for determining whether the observed behavior reflects intrinsic physics or extrinsic sample variation. The paper’s electrochemical growth method is presented as a way to produce more chemically homogeneous crystals that may help address this issue.