Superconductivity of Non-Strained PbTe-PbS and Strained PbTe-SnTe Superlattices

Abstract

A comparative study of structural and superconductive properties of semiconductor epitaxial superlattices PbTe-SnTe and PbTe-PbS grown on (001) KCl has been carried out. It has been found that the superconductivity of the PbTe-SnTe superlattices is caused by the stretching strain in the SnTe layers and it may be connected with the relative positions of L+8 and terms of PbTe and SnTe, respectively in the heterojunction. In contrast to the PbTe-SnTe superlattices, the superconductivity of the PbTe-PbS superlattices is found to be associated with regular misfit dislocation grids which are generated at the interfaces. Superconducting semiconductor superlattices having the critical temperature much higher than that of bulk semiconductors [1,2] are of special interest to those who are interested in the high temperature superconductivity models. Such materials as PbTe, PbSe and PbS are not superconductors, and SnTe is a superconductor at 0.22 K. Therefore, it may be supposed that the superconductivity of the superlattices made of those materials is connected with some pecular electron *This work is supported in part by Project N62-064 P.P. and USSR HTSC Project N364.(329)

SnTe Phase Transition in Strained Superlattices PbTe/SnTe

“…The observation of superconductivity in PbTe/SnTe superlattices (SL) [1] and its subsequent investigation [2][3][4] attracted attention to their galvanomagnetic properties.…”