Effects of alloying elements on structural, electronic and mechanical properties of AlSc2 by first-principles calculations

The structural, electronic and mechanical properties of AlSc2 intermetallic compound doped with Ti, V, Cr, Y, Zr, Nb, Mo and La elements have been calculated by using first-principle calculations based on density functional theory within GGA. It is found that microalloying with different elements has significant effect on AlSc2. From the calculated impurity formation energy, only doping with rare earth elements Y and La lessens the stability of AlSc2, so we no longer consider them. Doping of these transitional metal elements decreases the lattice parameters to a different extent. The band structure suggests that the doped AlSc2 also exhibits metallic properties, and the density of states and the charge density are also analyzed. The isotropic bulk modulus B, shear modulus G, Young’s modulus E of each system are obtained using the Voigt–Reuss–Hill averaging scheme. The B/G ratio and microhardness are calculated to determine the brittle and ductile behaviors and stiffness, respectively. Three shear factors i.e. A1, A2 and A3 for hexagonal crystal and the percentage anisotropy in compression and shear, are used to estimate elastic anisotropy.