Influence of Adatoms on the Vacancy Growth of Faceted Pores in a Crystal Under Mechanical Load

Abstract

The process of growth of faceted pores in a crystal under the influence of an applied mechanical load is considered in the framework of the classical Barton-Cabrera-Frank model, taking into account the presence of adatoms on the surface of pore faces. The growth is caused by the flow of excess vacancies from the bulk of the crystal, which arise due to tensile stresses. The recombination of advacancies and adatoms on the surface of pores is taken into account, and it is shown that as a result, a flow of adatoms from steps and fissures to the terrace can occur. This additional flow contributes to the growth of pores under load and, under certain conditions, can be the predominant mechanism of mass transfer, which must be taken into account for a correct assessment of the growth rate and lifetime of the crystal under load before failure. Expressions are obtained for the dependence of the pore growth rate on the applied mechanical load, the diffusion coefficients of vacancies and adatoms, and the rate of their recombination.