The H-T and P-T phase diagram of the superconducting phase in Pd:Bi$_2$Te$_3$

Abstract

We study the magnetic field vs temperature ($H$--$T$) and pressure vs temperature ($P$--$T$) phase diagram of the $T_c \approx 5.5$~K superconducting phase in Pd$_x$Bi$_2$Te$_3$ ($x \approx 1$) using electrical resistivity versus temperature measurements at various applied magnetic fields ($H$) and magnetic susceptibility versus temperature measurements at various applied magnetic fields ($H$) and pressure ($P$). The $H$--$T$ phase diagram has an initial upward curvature as observed in some unconventional superconductors. The critical field extrapolated to $T = 0$~K is $H_c (0) \approx 6$--$10$~kOe. The $T_c$ is suppressed approximately linearly with pressure at a rate $dT_c/dP \approx -0.28$~K/GPa.