The comparison between the pseudo gap opening temperatures in different cuprate superconductors with two CuO2 planes

The pseudo gap temperature T* was determined for some single crystal and po lycrystalline superconductors which have two CuO2 planes by rho (T) measure ment. The experimental results indicate that the normalized pseudo gap temp erature, namely T*/T-c(max), decreases with increasing T-c/T-c(max). The cu rves of T*/T-c(max) vs. T-c/T-c(max) plotted using our experimental data, a s well as the other authors' results reported previously, display an identi cal trend. This identity reveals that the relationship between T*/T-c(max) and T-c/T-c(max) is intrinsic for high temperature cuprate superconductors with two layers of CuO2.