Estimation of the Filling Factor of the High Tc Superconducting Phase in Y-Ba-Cu-O Mixed System

Abstract
A method to estimate the filling factor f of the high T c superconducting materials from the infrared reflection measurement is presented. It is shown that the Y-Ba-Cu-O mixed phase system can exhibit the characteristic superconductive resistance behaviours near 90 K in the samples with the filling factor less than 0.1.