The mechanical and thermodynamic properties of α-Na3(U0.84(2),Na0.16(2))O4: A combined first-principles calculations and quasi-harmonic Debye model study

Abstract

The mechanical properties of α-Na3(U0.84(2),Na0.16(2))O4 have been researched using the first-principles calculations combined with the quasi-harmonic Debye model. The obtained lattice parameters agree well with the published experimental data. The results of elastic constants indicate that α-Na3(U0.84(2),Na0.16(2))O4 is mechanically stable. The polycrystalline moduli are predicted. The results show that the α-Na3(U0.84(2),Na0.16(2))O4 exhibits brittleness and possesses obvious elastic anisotropy. The hardness shows that it can be considered a “soft material”. Furthermore, the Debye temperature θD and the minimum thermal conductivity kmin are also discussed, respectively. Finally, the thermal expansion coefficient α, isobaric heat capacity CP and isochoric heat capacity CV are evaluated through the quasi-harmonic Debye model.

Keywords

• Trisodium uranate
• Mechanical properties
• Thermodynamic properties
• The first-principles calculations
• The quasi-harmonic Debye model