First-principles investigation on the structural and elastic properties of cubic-Fe2TiAl under high pressures

摘要: The structural, elastic, and thermodynamic properties of cubic-Fe2TiAl under high temperatures pressures are investigated by performing ab initio calculation using the quasi-harmonic Debye model. Some ground state such as lattice constant, bulk modulus, pressure derivative elastic constants in good agreement with available experimental results theoretical data. Fe2TiAl thermal expansion coefficient, temperature, heat capacity ranges 0 K—1200 K GPa—250 GPa also obtained. indicate that capacities at different all increase temperature increasing close to Dulong—Petit limit higher temperatures, decreases increasing, increases rising. is stable mechanically 250 GPa. Moreover, lower pressure, coefficient rises rapidly rate becomes slow pressure.