Point Defects in Metals

Abstract

Calculations of the properties of point defects in metals by computer simulations have the enormous advantages over other classes of materials since, to first order, charge exchange and angular forces can be neglected, thereby greatly reducing the computational effort. Moreover, the structure, concentration and diffusivity of both the vacancy and interstitial defects are known experimentally in a number of metals, so that a solid base of information is available to validate the simulation models employed. In this article we will first briefly summarize this base of experimental knowledge and then discuss current state of the art methods for calculating the properties of defects in metals, citing notable successes and failures. Each subsection is laid out discussing first the ground state energies of the defect structures, then the defect concentration (or entropy), and finally the migration properties of the defects. In the last section, we will briefly examine attempts to apply the concepts of defect structures in crystalline structures to metallic glasses.