Superconducting properties of (Pb0.05Sn0.95)Te doped with indium under conditions of hydrostatic compression

Abstract

The superconducting properties of Pb_0.05Sn_0.95Te semiconductor alloy doped with 5 at % of In are investigated at a hydrostatic pressure of P < 7 kbar. At increasing pressure P > 1.35 kbar and T ≥ 1.3 K, the resistivity step to ρ = 0 in the temperature and magnetic-field dependences ρ(T) and ρ(H), which corresponds to the transition to the superconducting state, disappears. The experimental results are indicative of a decrease in the density of states at the Fermi level with increasing pressure, which can be interpreted as an indium-level shift deep into the valence band. The obtained data refine and supplement the results of studies devoted to investigation of the baric dependences of the critical parameters of the superconducting transition in (Pb_zSn_1–z)_0.95In_0.05Te with varying lead content z.