MOLECULAR-DYNAMICS SIMULATIONS OF PREMELTING PROCESSES IN CR2O3

Molecular-dynamics simulations of the (0001) surface of Cr2O3 were car ried out in the [300-2800 K] range of temperatures using a classical P auling-type pair potential. The analysis of the structural data shows a strong surface relaxation in agreement with experiment. Both static and dynamic surface properties indicate that a surface melting process occurs well below the melting point, which is estimated to be about 2 500 K, in excellent agreement with the experimental value of 2556 K. T he diffusive properties of this disordered phase are described and it is found that the main mechanism for diffusion involves hopping of sur face atoms.