ANALYSIS OF PARTIAL SUBSTITUTIONS IN ONE CU-O LAYER SUPERCONDUCTORS

In the paper a model is proposed that is able to explain the supercond uctor volume/total volume fraction shape vs. the doping concentration for copper oxide-based superconductors with a single Cu-O layer. The r esults of this model are in good agreement with the experimental deter minations. The model is based on a postulate-the necessity for loss of overlap of copper and oxygen orbitals for the appearance of supercond uctivity, i.e., a distortion of superconducting layers. The distortion is achieved by substituting a kind of ion from the parent compound wi th another kind of ion that have different charge in comparison with t he former. The electrostatic interactions of the doped ions with the l attice lead to superconductivity.