Pressure-driven valence increase and metallization in the Kondo insulator Ce₃Bi₄Pt₃

We report the results of high pressure x-ray diffraction, x-ray absorption, and electrical transport measurements of Kondo insulator Ce₃Bi₄Pt₃ up to 42 GPa, the highest pressure reached in the study of any Ce-based Kl. 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 energy gap and development of a semimetallic ground state. We also discuss potential ramifications of these results for the predicted topological KI state.