First-principles study on the mechanical properties and thermodynamic properties of Mo–Ta alloys

The mechanical properties, thermodynamic properties and electronic structure of Mo_1−xTa_x (Mo–Ta) alloys (x = 0, 0.0625, 0.125, 0.25, 0.3125, 0.5 and 1) were calculated by using firstprinciples. The electronic structure of Mo–Ta alloys was analysed by the projected density of states (PDOS). The low temperature heat capacity was estimated by Fermi energy and Debye temperature. It is shown that the formation enthalpy will decrease with the increase of Ta content, and the cohesive energy will increase with the increase of the Ta content. On the other hand, the addition of Ta atoms will reduce the strength and improve the ductility of Mo–Ta alloys, the Debye temperature will decrease and the low temperature heat capacity will be improved with the increase of the Ta content. All these results will be useful for the research of new plasma grid (PG) materials, which is mainly used in neutral beam injection (NBI) systems to produce negative hydrogen ions.