Superconductivity and Phase Transitions in Compressed Si to 45 GPa

Abstract

A diamond-anvil cell is used to measure the pressure dependence of the superconducting transition temperature $T_c$ in both primitive hexagonal and hexagonal-close-packed Si up to 45 GPa. The experimental results verify the prediction of superconductivity in hcp Si and the measured curve of $T_c$ versus pressure is found to be in good qualitative agreement with theory, in contrast to a recent experiment by Lin et al. who claim complete disagreement with theory.