LOW-FREQUENCY CHARGE-DENSITY EXCITATIONS AND HIGH-T-C SUPERCONDUCTIVITY IN CUPRATE METAL-OXIDE COMPOUNDS .1. THE HTSC PROBLEM PRIOR TO A DISCOVERY OF THE HIGH-T-C SUPERCONDUCTORS - PREDICTIONS AND PREMISES

In this review the history of evolution and the present state of the a rt or both the experimental and theoretical aspects of high-T-c superc onductivity is analysed and a possibility is discussed of describing a bnormal behavior of HTSC materials both in the normal and superconduct ing states using the conventional methods of the modern theory of soli d, based on Cooper pairing of charge carriers with regard to possible non-phonon mechanisms of electron interaction.