First‐Principles Study of Mechanical Properties, Electronic Structure, High‐Temperature and High‐Pressure Properties of Au–Ga Intermetallic Compounds

Based on density functional theory, four Au‐Ga intermetallic compounds (IMCs: AuGa 2 , Au 7 Ga 2 , AuGa, Au 2 Ga) are explored. First‐principles calculations disclose that among them, AuGa boasts the optimal thermal stability, whereas Au 7 Ga 2 has the poorest. The large bulk modulus of Au 7 Ga 2 implies strong compression resistance. In contrast, AuGa 2 shows inferior mechanical properties. These IMCs, with relevant values greater than 1.75 (for modulus values) and Poisson's ratios above 2.6, are ductile. Analyses of density of states suggest Au 7 Ga 2 and Au 2 Ga form sturdier bonds. Debye temperature results show Au 7 Ga 2 has the strongest interatomic bonding, Au 2 Ga the weakest. Thermal expansion of AuGa 2 /Au 7 Ga 2 aligns with Au, and Au 2 Ga is less stable. This study guides medium‐to‐high temperature Au–Ga welding.