Post-Irradiation Modulation of Distribution of Interacting Vacancies in the Elastically Anisotropic B.C.C. Crystals

Abstract

Spinodal mechanism of formation of a modulated structure in a spatial distribution of vacancies within the body-centred cubic (b.c.c.) crystal after irradiation is considered. The criterion of modulated-structure formation for the closed interacting-vacancies subsystem within the elastically anisotropic b.c.c. crystal is estimated. As shown, in case of positive factor of elastic anisotropy (ξ>0 as for Mo, Nb, W crystals), the modulated structures can be formed along the [111] direction, and in case of negative factor of elastic anisotropy (ξ<0 as for Fe crystal), the modulated structure can be formed along the [100] direction. Dependence of the modulated-structure period of b.c.c.-Mo (Fe)–vacancies’ solution on temperature is plotted. Period of a modulated structure in a spatial distribution of vacancies, which is formed by means of the spinodal mechanism, increases with temperature and is determined by the entropy factor, ‘(electro)chemical’ interaction of vacancies, and elastic properties of b.c.c. crystal.

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