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I. G. RATISHVILIA model describing the Frenkel pair annihilation process in a frse b.c.c. lattice is extended to the case of the lattice subjected to external stresses. It is assumed that new conditions of the annealing can be considered in the calculations by a relevant modification of the field of potential barriers dividing the different positions of the Frenkel pair components.MoAenb onmcbmamrqafl nposecc aHHHrmafiqmi nap +peHHena B cB060A~oji OUIC pememe pacnpocTpameTcfi Ha caysaB pememn Haxo,xfiwe~ca no^ BHemHm HanpaXeHkleM. IlpeAnOJraraeTCfi, 9 T O HOBbIe yCJlOBHR OTXHI' a MOrYT 6bITb Y9TeHbl B paC9eTaX IIOCpeACTBOM COOTBeTCTBYIO~efi MOAH@HKBUHEI IIOJIH IIOTeHUllaJIbHbIX Gapbepo~, pa3-Aensmrqnx coceAHHe noa~qmm HoMnoHeHT @peHHeaeBcmx nap.
IntroductionIn the previous papers [l, 21 we described the process of the thermally activated annihilation of vacancy-interstitial or, as they are called, Frenkel pairs in an unstressed lattice. In [l] the initial model, the set of basing assumptions, and the general scheme of calculations were formulated, while in [Z] the details of calculations, the numerical results, and the set of relevant experimental data were presented. The theory was applied to the case of Frenkel pairs created in the b.c.c. lattice of cr-iron, which was assumed to be free from any external stresses.Extension of the given model to the case of a statically compressed lattice is the aim of the present investigation.I n [l, 21 two fundamental assumptions were made: it was assumed that the interstitial dumbbell of the type (110) moves towards the vacancy, retaining its axis oriented along a fixed direction, and it was assumed, next, that the specific form of the potential relief near the components of the Prenkel pair allow the system of interrelated equations of motion to be reduced to a set of non-interrelated equations.The first postulation, concerning the constancy of the dumbbell axis orientation in the space, imposes significant restrictions upon the possible configurations of the tracks which lead the interstitials to the vacancies. As a result, a reduction of the pair annihilation probability arises, which creates some doubt with respect to the ability of the chosen scheme of description to reproduce the experimental data. The recent publications, however, make the restrictions imposed upon the interstitial tracks physically meaningful and thus support the chosen scheme of description. I n particular, by means of using elastic after-effect measurements it was shown [3, 41 that there exists no evidence that the dumbbell in the b.c.c. lattice of molybdenum reorients during diffusion. Thus, it can be concluded that at least in one of l) Tbilisi 380077, USSR.
