SUPERLATTICES OF HIGH-TC SUPERCONDUCTORS

Our plasma theory of superlattices of superconducting oxides in a tight-binding random-phase approximation (TBRPA) has been extended to the generalized random approximation for tight-binding superlattices (TBGRPA). We find that there is no important difference between TBGRPA and TBRPA. The superconducting transition temperatures Tc of the mixed Bi-Tl oxide superlattices are shown to depend predominantly on the maximum number of successive CuO2 layers within a supercell. © 1990 The American Physical Society.