MICROPORE FORMATION MECHANISMS IN GAMMA-AL2O3

A set of twenty molecular dynamics simulations of the surface of gamma -Al2O3 were performed at different densities and temperatures in order to investigate the formation mechanisms and structure of micropore sy stems. It is found that a severe reconstruction takes place at high de nsities which involves ion migration and a partial amorphization proce ss of the surface. At low densities a different process takes place wh ich does not involve ionic migration but only a local atomic rearrange ment. The statistics of size distribution and volume per unit mass cal culated from the molecular dynamics simulations are within the ranges experimentally obtained and theoretically predicted.