A Model B.C.C. Iron Including Angular Interactions. The Self‐Interstitial

Abstract

Self-interstitial configurations in Fe are simulated using an embedded-atom-method (EAM) interatomic potential and an embedded-defect (ED) one recently developed by the authors. The latter potential includes angular-dependent many-body local terms. Formation energy and lattice distortion for the (110) and (111) oriented dumbbells are calculated. The relative contributions of the pair and many-body interaction terms to these properties are discussed. Comparisons with other many-body potentials from the literature are made.

Self-Interstitial Configuration in B.C.C. Metals. An Analysis Based on Many-Body Potentials for Fe and Mo

“…Fe [6,17,18]. Here we extend those studies and add Mo, the main emphasis being, however, on the analysis of stability and its relationship with interstitial migration.…”

“…Finally, Johnson and Oh [26] developed simple EAM interatomic potentials for several b.c.c. metals including Fe and Mo, that were later modified by Guellil and Adams [27]; to their version for Fe we call JO [18]. Some of our former defect calculations in Fe used HVC, CB, and JO potentials slightly modified with respect to the original versions.…”

“…Some of our former defect calculations in Fe used HVC, CB, and JO potentials slightly modified with respect to the original versions. The changes allowed for smooth function joints in the case of CB potential, continuous cutoff up to the second derivative in HVC, and a more precise fitting of the Fe bulk modulus in JO (see Appendix in [18]). …”

“…The dependence of the energy on bond angles is thought to be important in b.c.c. transition metals [22], however, few studies on point defects in these metals are found in the literature using angle-dependent potentials [17,18,23].…”

Molecular-Dynamics Study of Self-Interstitial Diffusion in bcc-Iron

“…Most calculations [3][4][5][6][7][8] give higher heat of formation to the h111i dumbbell than to the h110i dumbbell at ground state, and naturally we consider that the h111i dumbbell is at an excited state from the h110i dumbbell (see Fig. 1).…”