Octahedral defects in a b.c.c. lattice examined by lattice theory

Abstract

Displacements of atoms, induced by single or multiple interstitials located at octahedral sites in a b.c.c. lattice, were examined using an eigenstrain method in lattice theory with the harmonic approximation. It is shown that the assignment of proper eigenstrains yields the correct magnitude of the potential energy for hydrogen, carbon and nitrogen in α-iron. It is also shown that the precipitate structure of Fe 16N 2 proposed by Jack takes a minimum potential energy among various kinds of plausible interstitial agglomerates.