Insights into the Effect of Vacancies on the Stability, Mechanical, Electronic, Thermodynamic, and Optical Properties of C40‐WSi2 Using First‐Principles Studies.

Herein, the effect of different atomic vacancies on the properties of C40‐type WSi2 are investigated. The formation energy, elastic properties, phonon, electronic structure, thermodynamic, and optical properties of C40‐type WSi2 are calculated. Calculations reveal that W vacancies are more likely to form in WSi2, and no imaginary phonon frequencies are detected in the phonon dispersion curves. Vacancies slightly enhance the ductility of C40 WSi2, with W vacancies performing better than Si vacancies. These vacancies weaken the W—Si and Si—Si bond strengths, affecting the elastic modulus but increasing the ductility of WSi2. The electronic properties indicate that C40‐WSi2 is a semiconductor. From the electronic structure analysis, it is clear that the W atomic vacancy can transform WSi2 from semiconducting‐to‐metallic properties. The effects of vacancies on the thermodynamic and optical properties of WSi2 are explored. This research contributes to the development of excess metal silicides as potential high‐temperature materials for later use. [ABSTRACT FROM AUTHOR]