First principles investigation of point defect-related properties in Ti2AlN

Abstract

The formation and migration energies of the mono-vacancies, foreign impurities (H, He and O atoms) and interstitials in Ti₂AlN have been investigated using first principles calculations. The results have shown that the mono-vacancy formation is energetically most favorable for the Al atom. There are three stable configurations for the foreign impurities, the Al-layer triangle center site, the interstitial site (⅓,⅔,0.6578) and the vacancy site. It was also found that the O substitution is easily formed. For interstitials, the octahedral interstitial (Ti, N, H or O) and Al-layer triangle interstitial (Al or He) sites were observed in our simulation. Moreover, the H, O and N interstitials are dominant in Ti₂AlN. These results could provide theoretical guidance for future experiments and for the application of Ti₂AlN.