First-principles investigations on structural stability, mechanical, and thermodynamic properties of LaT₂Al₂₀ (T=Ti, V, Cr, Nb, and Ta) intermetallic cage compounds

First principles calculations were used to explore the structural stability, mechanical properties, and thermodynamic properties of LaT₂Al₂₀ (T=Ti, V, Cr, Nb, and Ta) intermetallics. The calculated formation enthalpy and phonon frequencies indicate that LaT₂Al₂₀ intermetallics exhibit the structural stability. The elastic moduli (B, G, E, and H_v) indicate that these intermetallics possess the better elastic properties than pure Al. The values of Poisson's ratio v and B/G demonstrate that LaT₂Al₂₀ intermetallics are all brittle materials. The anisotropy of elasticity and Young's modulus (three- and two-dimensional figures) indicate that LaT₂Al₂₀ compounds are anisotropic. Importantly, the calculated thermal quantities demonstrate that LaT₂Al₂₀ intermetallics possess the better thermal physical properties than pure Al at high temperatures.