A simple statistical phenomenological model for cation substitutions in Nd_1+xBa_2−xCu₃O_7−δ+x/2

Abstract

The first results are presented of calculations using a quite simple phenomenological model developed to simulate the cationic substitutions in Nd_{1+ x} Ba_{2− x} Cu₃O_{7+ x /2−δ} (Nd123). Although elementary concepts from statistical mechanics are used in the model, significant results have been obtained, such as the reconstruction of the substitution region limits and their dependence on temperature. Particularly interesting is the prediction of strong temperature dependence for the minimum substitution parameter, x _min.

Keywords:

• cuprate superconductors
• NdBaCuO
• phase diagrams
• solid solution