Pressure studies in filled skutterudite La_0.8Rh₄P₁₂

Filled skutterudite LaxRh4P12 has the highest superconducting transition temperature (T-c) of 17 K [1]. An analysis of superconducting parameters of LaxRh4P12 suggests that the relatively large the electron-phonon coupling constant lambda among the ternary filled skutterudite-type phosphides is one of the reasons why it has high T-c. In this study, high-pressure electrical resistively measurements for LaxRh4P12 at x = 0.8 with T-c = 13.6 K using a piston cylinder device and a diamond anvil cell have been carried out up to 15 GPa. T-c decreases with applying pressure at a rate of -0.5 K/GPa. High-pressure x-ray diffraction measurements have also been performed up to 5 GPa. The value of B-0 of 120 GPa is calculated from the x-ray data.