Superconductivity under pressure and low temperature specific heat of ThPr alloys

Abstract

Measurements of superconducting transition temperature under pressure and low temperature specific heat are presented for ThPr alloys. At 18.2 kbar the normal- to superconducting-state phase boundary extends beyond 50at.% Pr. This system is discussed in terms of a non-magnetic singlet ground state for the Pr3+ ions due to crystal field splitting. A splitting scheme which varies with Pr concentration is proposed.