Thermophysical properties of interaction layer (IL) formed in U-Mo/Al dispersion fuel are important for the evaluation of its impact on the fuel performance. Binary and ternary phases observed in the IL, however, are not well studied yet. Recently we predicted the thermophysical properties of the binary U-Al compounds in U-Al system using density functional theory (DFT) calculations. In this paper, we investigated the structural, elastic, electronic, vibrational and thermodynamic properties of the ternary U-Mo-Al compounds formed in IL, including (U_0.75,Mo_0.25)Al₃, U₆Mo₄Al₄₃ and UMo₂Al₂₀, using DFT calculations. The polycrystalline aggregate properties of these compounds were obtained from the predicted single crystal elastic constants. The calculated electronic density of states confirm that all of the compounds exhibit typical metallic behavior with the majority states at the Fermi level dominated by U 5f electrons. Using quasi-harmonic approximation, we predicted the thermodynamic properties of these compounds by including both electronic and lattice contributions. We also investigated the effect of density on the thermodynamic properties of (U_0.75,Mo_0.25)Al₃ phase. The current results are expected to be helpful to the modeling of the fuel performance of U-Mo/Al dispersion fuel and the thermodynamic modeling of the ternary U-Mo-Al system.

U-Mo / Al分散燃料中形成的相互作用层（IL）的热物理性质对于评估其对燃料性能的影响非常重要。然而，在IL中观察到的二元和三元相还没有得到很好的研究。最近，我们使用密度泛函理论（DFT）计算预测了U-Al系统中二元U-Al化合物的热物理性质。在本文中，我们研究了在IL中形成的三元U-Mo-Al化合物的结构，弹性，电子，振动和热力学性质，包括（U _0.75，Mo _0.25）Al ₃，U ₆ Mo ₄ Al ₄₃和UMo ₂铝₂₀，使用DFT计算。这些化合物的多晶聚集体性质是从预测的单晶弹性常数获得的。计算得到的态电子密度证实，所有化合物均表现出典型的金属行为，其中大多数态在费米能级下受U 5 f电子支配。使用准谐波近似，我们通过包含电子和晶格贡献来预测这些化合物的热力学性质。我们还研究了密度对（U _0.75，Mo _0.25）Al ₃热力学性质的影响阶段。预期目前的结果将有助于U-Mo / Al分散燃料的燃料性能建模以及三元U-Mo-Al系统的热力学建模。