COOPER-PAIR FORMATION MECHANISM FOR HIGH-TEMPERATURE SUPERCONDUCTORS

In the conducting phase of HTS the copper cations possess the mixed va lence Cu1.5+ and labile superstoichiometric oxygen exists in the only O2- form. Phase transfer of copper valence segregation, leading to the alternation of Cu+ and Cu2+ cations in the lattice planes, causes an electron disproportion on the O2- centers. This process O2- + O2- reve rsible O2 + O2(2-) results in the formation of Cooper pairs on the O2( 2-) ions, which move coherently in the electric field through the free levels of the neighboring O2 molecules.