Semiconducting chalcogenide multilayers: structure and superconductivity

Superconducting properties study, X-ray diffractometry and TEM investigatio ns of the structure have been carried out on rather exotic superconducting multilayers consisting only of semiconducting materials (chalcogenides of P b, Sn and rare-earth elements). Superconductivity is discovered in a new co mbination of semiconductors PbSe/EuS. It is shown that essential features o f the multilayers structure determining the appearance of superconductivity are the perfect single crystallinity of entire sample and regular grids of misfit dislocations on the interfaces between two semiconductors. The segr egation of free Pb observed in some cases does not correlate with appearanc e of superconductivity. The possibility of dislocation-induced superconduct ivity is discussed. (C) 2000 Published by Elsevier Science B.V. All rights reserved.