Journal Article

Superconductivity in (Ba,K)SbO3

Takayama, Tomohiro, Isobe, Masahiko, Takagi, Hidenori, Sutarto, Ronny, Kim, Hun-Ho, Kim, Minu, McNally, Graham M., Kremer, Reinhard K., Yaresko, Alexander, Wedig, Ulrich, Oudah, Mohamed, Gibbs, Alexandra S., Green, Robert J., Bonn, D. A., Keimer, Bernhard, Manuel, Pascal

2022

Overview

(Ba,K)BiO 3 constitute an interesting class of superconductors, where the remarkably high superconducting transition temperature T c of 30 K arises in proximity to charge density wave order. However, the precise mechanism behind these phases remains unclear. Here, enabled by high-pressure synthesis, we report superconductivity in (Ba,K)SbO 3 with a positive oxygen–metal charge transfer energy in contrast to (Ba,K)BiO 3 . The parent compound BaSbO 3− δ shows a larger charge density wave gap compared to BaBiO 3 . As the charge density wave order is suppressed via potassium substitution up to 65%, superconductivity emerges, rising up to T c  = 15 K. This value is lower than the maximum T c of (Ba,K)BiO 3 , but higher by more than a factor of two at comparable potassium concentrations. The discovery of an enhanced charge density wave gap and superconductivity in (Ba,K)SbO 3 indicates that strong oxygen–metal covalency may be more essential than the sign of the charge transfer energy in the main-group perovskite superconductors. High-pressure synthesis is used to stabilize superconducting (Ba,K)SbO 3 , whose properties provide a fresh perspective on the origin of superconductivity in these types of materials.

• Publisher: Nature Publishing Group UK,Nature Publishing Group
• Subject: 119/118 / 140/133 / 639/301/119/1003 / 639/766/119/995 / Biomaterials / Charge density waves / Charge transfer / Chemistry and Materials Science / Condensed Matter Physics / High pressure / Materials Science / Nanotechnology / Optical and Electronic Materials / Oxygen / Perovskites / Potassium / Superconductivity / Superconductors / Synthesis / Transition temperature / Transition temperatures