Superconductivity under Pressure in(U1−xThx)Be13: Evidence for Two Superconducting States

Abstract

The influence of pressure $P$ on the superconducting transition temperature $T_c$ has been determined for the $\left({\mathrm{U}}_{1-x}{\mathrm{Th}}_x\right){\mathrm{Be}}_{13}$ system. The magnitude of $\frac{d{T}_c}{\mathrm{dP}}$ increases by a factor of 3 for $x>\mathrm{}1.7\%$ where an increase of $T_c$ is observed at ambient pressure. The phase diagram of $T_c\mathrm{}\left(x\right)\mathrm{}$ for $P=10\mathrm{}$ kbar shows two distinct regions of superconductivity.