THE POSSIBLE ROLE OF COOPERATIVE JAHN-TELLER EFFECT IN THE HIGH-T(C) SUPERCONDUCTIVITY

The sistems La1Ba2CuxOy, La1Mg2CuxOy, La1Ba2CuxMg3-xOy, Y1Ba2CuxOy, La 1Sr2BaxOy, La1Sr2Cu3Oy, La1Sr2CuxZn3-xOy have been investigated by ESR -method. It has been shown that Cu(2+) ions are placed in planesquare environment with the basic d(x2-y2)-orbitals of unpaired electron when 0,01 < x < 1. The presence of lanthanum or yttrium results in the coo perative Jahn-Teller's regulating of copper ions to chaines.At increas ing of the copper concentration these chaines form the CuO2 layer that is responsible for the high-T(c) superconductivity. It has been sugge sted that high-T(c) superconductivity probably exists in compounds, wh ich don't contain copper. The formation of the dimers of V(4+) ions Si O2 and CaO oxides has been demonstrated. This fact supports the hypoth esis that it is possible to synthesise high-T(c) superconductors with the conductive layer that consists from V(4+) ions.