AN EXPLANATION FOR THE RISE IN TC IN THE TL-BASED AND BI-BASED HIGH-TEMPERATURE SUPERCONDUCTORS

Using the plasmon exchange model for the high-Tc superconductor, the authors show that the Tc rises with an increase in the number of CuO layers per unit cell, which is in agreement with recent observations in the Tl- and Bi-based compounds. Their calculation also shows that there is a saturation effect, i.e. that Tc cannot be raised indefinitely by increasing the number of CuO layers.