Pressure-Driven Valence Increase and Metallization in Kondo Insulator Ce${}_3$Bi${}_4$Pt${}_3$

Abstract

We report the results of high pressure x-ray diffraction, x-ray absorption, and electrical transport measurements of Kondo insulator Ce${}_3$Bi${}_4$Pt${}_3$ up to 42 GPa, the highest pressure reached in the study of any Ce-based KI. We observe a smooth decrease in volume and movement toward intermediate Ce valence with pressure, both of which point to increased electron correlations. Despite this, temperature-dependent resistance data show the suppression of the interaction-driven ambient pressure insulating ground state. We also discuss potential ramifications of these results for the predicted topological KI state.

8 pages, 5 figures