Thermal expansion path, mechanical and thermodynamic properties of C14 Fe2Nb Laves phase calculated using density functional theory

Thermal expansion anisotropy, elastic, thermal and thermodynamic properties of C14 Fe 2 Nb Laves phase have been studied using first-principles based quasi-harmonic Debye - Grüneisen approximation. The search for thermal expansion was carried out by a new simplified method, which allows to reduce the problem to a one-dimensional case. The electronic, vibrational and magnetic subsystems were taken into account. The free energies of Fe 2 Nb were calculated along different thermal expansion paths. A path with the least free energy was considered as a direction of thermal expansion. The thermal expansion of Fe 2 Nb is not isotropic. The influence of electronic, magnetic and vibrational entropies on the stability of Fe 2 Nb is studied. The isobaric heat capacity , thermal expansion, coefficients of elasticity of the strain tensor , bulk modulus , sound wave velocities, Debye temperature , and thermal conductivity are reported. The calculated results analyzed and are in an agreement with the available experimental data. A new enhanced understanding into thermal expansion behavior of the Laves phases has been obtained, which can provide an insight into future material developments.