Frenkel Defects and Interstitial Atoms in Periclase (MgO) at High Temperature by Molecular Dynamics Simulation

Abstract

an analysis program was newly developed to explore the vacancies and interstitial atoms and to determine atomic migration, i.e., atomic diffusion. We applied this program to the results calculated by the molecular dynamics (Md) simulation of periclase (MgO) in which Schottky defects (vacancies) were not initially introduced. Generation, migration and extinction of Frenkel defects and interstitial atoms for only magnesium ion were first observed at high temperature in this Md system and they strongly corresponded to the change of the mean square distance (MSd) of magnesium ion in Md system. On the other hand, we could not observe Frenkel defects and interstitial atoms for oxygen ion and MSd value of oxygen ion had almost constant value. Generation, migration and extinction of Frenkel defects and interstitial atoms cannot be ignored for the diffusion process at high temperature.