Investigation on structural stability, mechanical properties of AuAl2 doped with Y, Sc and Ta based by first -principles

In this work, in order to provide theoretical data for further research on preparing AuAl2 alloy to screen suitable elements that can improve the ductility of AuAl2, the first-principles calculations were performed to investigate the effects of doping Y, Sc and Ta on the structural stability, mechanical properties and thermal conductivity of AuAl2. The results show that the structural stability is the best when Y atom occupied the octahedral gap position, and Y and Ta both are able to improve the toughness of AuAl2, while the improvement of mechanical properties of AuAl2 is not obvious under the effect of doping Sc. When Y atom occupies the Al atom position, the mechanical properties are the best, and the hardness and toughness values reach 1.26 GPa and 4.47 MPa & sdot;m1/2, respectively. In addition, the effects of doping elements on the electronic structure, electrical conductivity, sound speed, Debye temperature and thermal conductivity of AuAl2 alloy are also considered.