The influence of vacancy defects on elastic and electronic properties of TaSi (5/3) desilicides from a first-principles calculations. Issue 8 (1st June 2020)

• Record Type: Journal Article
• Authors: Chen, Jiaying; Zhang, Xudong; Ying, Caihong; Ma, He; Li, Jun; Wang, Feng; Guo, Hui
• Is Part Of: Ceramics international. Volume 46:Issue 8(2020)Part A
• Page Start: 10992
• Page End: 10999
• Publication Date: 2020-06-01
• Subjects: Vacancy points -- Mechanical properties -- Electronic structure -- First -principle calculations; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2020.01.115
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: As so far, the investigation and application of transition metal silicon-based materials have attracted wide attention. Tantalum-based silicides are one of the most important silicon-based high-temperature materials. But the brittle behavior hinders their wide applications. Here, the influence of vacancies on mechanical properties, brittle/ductile behavior and electronic properties of Ta5 Si3 desilicides has been investigated using the first-principles calculations. The vacancy formation energy, elastic constants, elastic moduli, brittle/ductile behavior and electronic behavior of the perfect Ta5 Si3 and Ta5 Si3 with vacancies were comparatively calculated and discussed, respectively. The thermodynamic data and phonon dispersions demonstrate that the available Ta vacancies in Ta5 Si3 can exhibit the better stability than Si atomic vacancies in Ta5 Si3 desilicides. In addition, although the vacancies weaken the hardness of the parent Ta5 Si3, the vacancies improve the brittle behavior of the parent Ta5 Si3 . Especially, the Ta-Va1 vacancy in Ta5 Si3 induced brittle-to-ductile transition for parent Ta5 Si3 desilicides. The electronic structures explain the mechanism of the different vacancies effect on mechanical properties.