Theoretical study of the effects of vacancy and oxygen impurity on Ti2GaC) *Project supported by the National Magnetic Confinement Fusion Science Program of China (Grant No. 2014GB104002), the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDA03030100), and the National Natural Science Foundation of China (Grant Nos. 11275156 and 11304324). (August 2015)

• Record Type: Journal Article
• Authors: Chen, Jun-Jun; Duan, Ji-Zheng; Zhao, Da-Qiang; Zhang, Jian-Rong; Yang, Yang; Duan, Wen-Shan
• Is Part Of: Chinese physics B. Volume 24:Number 8(2015:Aug.)
• Page Start: 201
• Publication Date: 2015-08
• Subjects: Physics -- Periodicals; Physics; Periodicals; 530.05
• DOI: 10.1088/1674-1056/24/8/088101
• Languages: English
• ISSNs: 1674-1056

Abstract

<abstract> <title>Abstract</title> <p>This paper presents the mono-vacancy formation and migration energies of each element Ti, Ga, and C in the <italic>MAX</italic> phase Ti₂GaC, which are obtained by first principles calculations. We also calculate the formation energies of oxygen substituting for Ti, Ga, and C and two formation energies of oxygen interstitial in different sites. The results show that the formation energy of oxygen substituting for Ti is the highest, and the formation energies of the O substitution for Ga atoms decrease as the oxygen concentration increases. The two different formation energies of one oxygen interstitial show that the stable site for the oxygen interstitial is at the center of the triangle composed by three Ga atoms. The effects of vacancy, oxygen substitution, and the interstitial on the electronic properties of Ti₂GaC are also discussed in light of the density of states and the electron charge density.</p> </abstract>