Direct diffusion through interpenetrating networks: Oxygen in titanium

Abstract

How impurity atoms move through a crystal is a fundamental and recurrent question in materials. The previous models of oxygen diffusion in titanium relied on interstitial lattice sites that were recently found to be unstable-leaving no consistent picture of the diffusion pathways. Using first-principles quantum-mechanical methods, we find three oxygen interstitial sites in titanium, and quantify the multiple interpenetrating networks for oxygen diffusion. Surprisingly, all transitions contribute to diffusion. © 2011 American Physical Society.