Crystal Chemistry of Superconductive Bismuth and Thallium Cuprates

Abstract

The superconductive rush has led to a considerable number of publications, which one often rather similar and are note always of high interest. Nevertheless, many results have been gathered about the 40K-La2CuO4 type and 92K-YBa2 Cu3 O7 type superconductors which allow superconductivity in those phases to be better undertood. These two families have been the purpose of numerous papers and several reviews and for this reason will not be discussed here. On the opposite, the bismuth and thallium cuprates which are born recently, have been less studied, perhaps owing to their more difficult chemistry. Thus the present review is mainly focussed on the synthesis, structure, non stoichiometry and extended defects of those latter phases in connection with their superconducting properties.