Structural, electronic, mechanical and thermodynamic properties of Cr–Si binary silicides from first-principles investigations. (March 2021)

• Record Type: Journal Article
• Authors: Pan, Y.; Pu, D.L.; Yu, E.D.
• Is Part Of: Vacuum. Volume 185(2021)
• Publication Date: 2021-03
• Subjects: Cr–Si silicides -- Mechanical properties -- Electronic properties -- Thermodynamic properties -- First-principles calculations; Vacuum -- Periodicals; 621.55
• DOI: 10.1016/j.vacuum.2020.110024
• Languages: English
• ISSNs: 0042-207X

Abstract

Abstract: Cr–Si binary silicides are promising advanced functional materials, which are widely used in semiconductors, thermoelectric and high temperature industries. However, the correlation between structural feature and the overall properties of Cr–Si silicides are not unclear. Here, we apply the first-principles to study the structural, mechanical, electronic and thermodynamic properties of Cr–Si silicides. The result shows that one novel Cr2 Si orthorhombic structure ( Pnma ) is predicted. It is found that the calculated bulk modulus of Cr–Si silicides decreases with increasing Si concentration. The calculated shear modulus and Young's modulus of Cr3 Si are larger than that of the other Cr–Si silicides because of the symmetrical Cr–Si bonds. However, Cr2 Si shows better ductility and good plasticity in comparison to the other Cr–Si silicides. Compared to the CrSi2, these Cr–Si silicides show better electronic properties. Finally, it is found that the calculated Debye temperature (ΘD ) of Cr–Si silicides obeys the sequence of Cr5 Si3 >CrSi > Cr3 Si > Cr2 Si. Naturally, the high-temperature thermodynamic properties of Cr–Si silicides are attributed to the vibration of Si atom and Cr–Si bond. This work provides a theoretical framework for understanding the comprehensive properties of Cr–Si silicides and provides powerful guidelines for future improving the overall performances of Cr–Si silicides. Highlights: The influence of Si concentration on the overall properties of Cr–Si silicides is studied. One novel Cr2 Si orthorhombic structure ( Pnma ) is predicted. The bulk modulus of Cr–Si silicides decrease with increasing Si composition. Cr2 Si exhibits better ductility and plasticity compared to the other Cr–Si silicides. The Debye temperature (ΘD ) of Cr–Si silicides obeys the sequence of: Cr5 Si3 >CrSi > Cr3 Si > Cr2 Si.