On electron pairing in unconventional superconductors

This paper presents a study whose aim is to decide whether the basic mechanism of electron pairing is the same for all unconventional superconductors such as perovskites, cuprates, organic compounds and alkaly-stuffed fullerene. By analyzing the features of these dissimilar materials, arguments are singled out showing that superconduction is originated by electrons combined in weakly bound pairs running in regions bordering on certain lattice discontinuities which are common to the structure of the superconductors dealt with. Special attention is devoted to the properties of the YBCO cuprate.