Analysis of partial substitutions in one Cu-O layer superconductors

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