MD simulation of crystal growth from MgO melt

Abstract

By molecular dynamics (MD) simulation crystal growth from supercooled MgO melt has been studied, whose crystal has an NaCl type. The model was similar to that previously applied for NaCl. Crystal growth of the melt on the crystal layers has been studied; 1400 or 1800 ions were disposed in an MD basic cell. The Gilbert-Ida-type pair potentials whose parameters were presented by Kawamura and Akamatsu were employed, with which the melting point simulated in a three-dimensional space was 2670 K, while the experimental m.p. is 3099 K. The cases were studied that the initial interfaces between crystalline and melt were the (100), (110) and (111) planes; crystal grew in the [100], 〈100〉 and [111] directions, respectively. For the (100) system the growth rate was studied at various temperatures and found to possess a maximum(ca. 90 m s −1) at about 2300 K. The mean square displacements on the x−y plane and in the z-direction were calculated. The overall profile of the growth feature of MgO is very similar to that of NaCl.