A simple statistical phenomenological model for cation substitutions in Nd1+xBa2-xCu3O7-(delta+x/2)

The first results are presented of calculations using a quite simple phenomenological model developed to simulate the cationic substitutions in Nd1+xBa2-xCu3O7+x/2-delta (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).