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

A comparative study of structural and superconductive properties of semi conductor 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$\text{}_{8}^{+}$ and L$\text{}_{6}^{+}$ terms of PbTe and SnTe, respectively in the heterojunction. In contrast to the PbTe-SnTe superlattices, the superconductivity of the PbTe-PbS super lattices is found to be associated with regular misfit dislocation grids which are generated at the interfaces.