A REFINED BCS APPROACH TO THE DOPING DEPENDENCE OF Tc IN HIGH-Tc SUPERCONDUCTORS

Abstract

The presence of dopant ions in a high-temperature superconductor (HTSC) is accounted for by introducing an effective temperature [Formula: see text] of current carriers. It is shown that the BCS formalism, with a power law for the bandwidth and state density dependence on dopant concentration x and a [Formula: see text] temperature scale, yields a closed formula for T c (x), which, in several cases, agrees well with experimental data on T c (x) of HTSCs.