Unraveling the Atomic Structure Evolution of Titanium Nitride Upon Oxidation

Abstract

In this study, state-of-the-art aberration-corrected environmental transmission electron microscopy is utilized to investigate the atomic-scale structural evolution of titanium nitride during dynamic oxidation. Titanium nitride oxidation originates from the migration of Ti atoms along {200} that results in two distinct reaction pathways, characterized by the formation of chains of titanium vacancies and staggered titanium vacancies. We demonstrate that titanium atoms exhibit varied oxidation activity on different crystal facets, with the selection of oxidation pathways significantly influenced by the curvature of the crystal surface, which is also supported by the First Principles Calculations.

Keywords: Titanium nitride, oxidation mechanism, Dynamic reaction, In situ ETEM, Phase Transition