Problem of super-high-Tc superconductivity

A possibility of a general path for the search of super-high-T-c (SHT) materials is discussed. The approach is based on the idea of enhancement of the basic parameters, entering the BCS formula for T-c: the electron-phonon interaction constant, the density of states and the energy of mediating quasiparticies. The known examples of materials with a relatively high-T-c are examined. The author's idea of finding a substance forming a crystalline excitonium phase (1978) is presented. Since the BCS formula represents only an isotropic model, the role of anisotropy is analyzed within the author's model for high-T-c layered cuprates. The main conclusion is, that anisotropy of the spectrum and a long-ranged interaction widens the options for obtaining SHT. (c) 2007 Published by Elsevier B.V.