Ab-initio calculations of mechanical and thermodynamic properties of TM (transition metal: 3d and 4d)-doped Pt3Al

The cubic Pt3Al has received considerable attention for high temperature applications. However, it is a great challenge to improve the balance between the mechanical properties and thermal stability. By means of ab-initio calculations, here, we systematically investigate the influence of transition metals on the mechanical and thermodynamic properties of Pt3Al. Owing to the d- orbit effect, we select 18 transition metals: nine 3 d-transition metals and nine 4 d-trantion metals, respectively. The results show that those dopant elements prefer to occupy the Al site in comparison to the Pt site because of the valence electronic density. We further find that Nb-doping is more thermodynamically stable than that of other transition metals. Importantly, those transition metals can effectively enhance the bulk modulus of Pt3Al. In particular, Nb-doping shows high bulk modulus in comparison to other transition metals. In addition, we find that the calculated Debye temperature of the Co-doping, Fe-doping, Ni-doping, Rh-doping and Ru-doping is larger than that of the parent Pt3Al. Therefore, we predict that Nb is an effective element to improve the balance between the mechanical and thermodynamic properties of the parent Pt3Al.