SIMULATION STUDY OF GRAIN-GROWTH IN LAYERED MATERIALS APPLICATION TO YBA2CU3O7-DELTA CERAMICS

We propose a simple lattice model which takes into account the anisotropy of grain formation energy to study the grain growth of layered materials such as polycrystalline superconducting cuprates. The anisotropic parameter in this model is estimated in the case of YBa2Cu3O7-delta via a semi-empirical theory for surface energy anisotropy. Monte Carlo simulation shows that the anisotropy of grain formation energy causes abnormal grain growth in which large elongated grains grow at the expense of fine matrix grains. The evolution with time of parameters characterizing the grain sizes and shapes have been calculated. In general, the results agree very well with experimental observation.