Superconducting transition in resistivity and magnetization of the solid solution (Pb0.4Sn0.6)0.8In0.2Te

Abstract

The temperature and magnetic field dependences of electrical resistivity ρ(Т, Н) and magnetization m(Т, H) of the semiconductor solid solution (Pb0.4Sn0.6)0.8In0.2Te were studied in the temperature range T = 2 K - 300 K (including the region of the superconducting transition of the compound T ≤ 4 K) and in magnetic fields H ≤ 140 kOe. The critical parameters of superconducting transition were determined: the critical temperature Tc ≈ 4 K and the second critical magnetic field at T → 0 K, Hc2(0) ≈ 27.5 kOe. The magnetic field - magnetization dependences m(H) at T < Tc region exhibit a hysteresis loop associated with the magnetic flux capturing by a polycrystalline superconducting sample. In magnetic fields close to the second critical Hc2(T) at temperatures T < 3 K, an additional maximum of the diamagnetic response on the forward branch and a symmetric paramagnetic maximum on the reverse branch were observed on the m(H) dependences, which we interpret as the peak-effect in magnetization of the superconducting solid solution. In the (Pb0.4Sn0.6)0.8In0.2Te sample, at the temperature Т = 2 K and the peak-effect field Нpeak = 16.5 kOe, the magnetization peak amplitude was ~ 6% of the maximum value of the Meissner response at H ≈ 0 Oe. On the basis of the obtained data the possible nature of the peak-effect in the magnetization of solid solutions (PbzSn1-z)1-хInхTe, at Т < Tc was discussed, influence of the vortex structure dynamics of the superconducting compound, the lead content in the solid solution, the level of In doping and external parameters was considered.