First-principles investigations on structural stability,mechanical, and thermodynamic properties of LaT_2Al_(20)(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 LaT_2 Al_(20)(T = Ti, V, Cr, Nb, and Ta) intermetallics. The calculated formation enthalpy and phonon frequencies indicate that LaT_2Al_(20) intermetallics exhibit the structural stability. The elastic moduli(B, G, E, and Hv) indicate that these intermetallics possess the better elastic properties than pure Al. The values of Poisson's ratio v and B/G demonstrate that LaT_2Al_(20) intermetallics are all brittle materials. The anisotropy of elasticity and Young's modulus(three-and two-dimensional figures) indicate that LaT_2Al_(20) compounds are anisotropic. Importantly, the calculated thermal quantities demonstrate that LaT_2Al_(20) intermetallics possess the better thermal physical properties than pure Al at high temperatures.