First principles study of stability, mechanical, and electronic properties of chromium silicides

Through the first principles calculations, the chemical stability, mechanical, and electronic properties of chromium silicides are predicted. Estimating enthalpies and binding energies, density state density and electron density distribution are combined to analyse the thermodynamic stability and physical properties of chrome-silicon binary compounds. The chromium silicide includes Cr3Si, Cr5Si3, CrSi, and CrSi2. The chemical stability and the information about electronic structure, mechanical properties, Debye temperature, and anisotropy properties are obtained by density functional theory and Debye quasi-harmonic approximation. Meanwhile, the calculation of elastic modulus shows that Cr3Si has the highest body modulus value (251 GPa) and CrSi2 possesses the highest shear modulus (169.5 GPa) and Young's modulus (394.9 GPa). In addition, the Debye temperature and the speed of sound of these Cr-Si compounds are also calculated. Since the calculated bulk modulus is different from Young's modulus anisotropy index, and also different from Young's modulus of a three-dimensional surface shape, the different mechanical anisotropies of all the compounds are obtained.