THE ELECTRON-TRANSPORT PHENOMENA IN Y-BASED HTSCS AND THEIR ANALYSIS ON THE BASIS OF PHENOMENOLOGICAL NARROW-BAND THEORY - THE BAND-STRUCTURE TRANSFORMATION WITH OXYGEN-CONTENT AND SUBSTITUTION FOR CU

The transport properties of YBa2Cu3Oy with various y and YBa(2)Cu(3-x) M(x)O(y) (M = Fe, Co, Ni, Mn) with various x have been studied. The re sults obtained have been analyzed on the basis of the phenomenological theory of electron transport in the case of a narrow conductive band. The narrow-band model permits one to account for the specific feature s of the transport coefficients of HTSC and to determine the band-stru cture parameters from comparison of the experimental and calculated te mperature dependences of the thermoelectric power. The dependences of band-structure parameters and superconductive properties on y and x ha ve been analyzed together. The differences in the influence of differe nt 3d metals on the band structure were revealed. Taking into account the crystallochemical-studies data we drew the conclusion that the oxy gen sublattice disordering has a determinant effect on band-structure parameters and superconductive properties of YBa2Cu3Oy.