Atomistic study of anomalous self-diffusion in bcc beta -titanium.

Abstract

In an investigation of self-diffusion in bcc $\ensuremath{\beta}$-Ti single crystals by means of both quasielastic and inelastic neutron scattering, the elementary diffusion jump has been determined directly, and the lattice vibrations which trigger the jump have been elucidated. The elementary jump for self-diffusion is a simple \textonehalf{} [111] jump into a nearest-neighbor vacancy. The reason for the anomalously fast self-diffusion is a fluctuation of $\ensuremath{\omega}$-phase type which facilitates jumps into neighboring vacancies.