Synergistic effects of alloy elements on the structural stability, mechanical properties and electronic structure of Ni3Sn4: Using first principles

Ni3Sn4 and Ni3Sn4-based ternary phases play an important role in the interfacial connection in solder joints. In this study, we provide a detailed investigation of the structural stability, mechanical properties and electronic structures of Ni3-xMxSn4 (M = Co, Pd, Pt and Cu，x = 0–1.5) and Ni3Sn4-xNx (NIn, Ge, Pb and Sb，x = 0–1.5) using first-principles methods. The calculated formation enthalpies reveal that the alloy elements (Pd, Pt, Ge and Sb) can improve the structural stability of Ni3Sn4, but Co, Cu, In and Pb do the opposite. The elastic constants (Cij) of Ni3-xMxSn4 and Ni3Sn4-xNx structures are typically lower than those of Ni3Sn4. Cu and Sb elements are detrimental to the ductility of Ni3Sn4, and the elements of Ge and Pb can improve the ductility of Ni3Sn4. The rest of elements (In, Co, Pd and Pt) have less influence on the ductility and brittleness of Ni3Sn4. Electronic structure analysis shows that the trend of the Fermi Level values (Ef) are consistent with the formation enthalpies (Hf) of Ni3-xMxSn4 and Ni3Sn4-xNx. The orbitals hybridization between Ni-d, M-d, Sn-p and N-p have a significant effect on Ni3Sn4. Finally, the bulk modulus (B), shear modulus (G), Young's modulus (E), Poisson's ratio (ν), and differential charge density are calculated completely. •A comparative study of Ni3-xMxSn4 and Ni3Sn4-xNx based on DFT.•The structural stability of Ni3Sn4-based ternary structures have revealed.•Pd, Pt, Ge, Sb improve the structural stability of Ni3Sn4.•Ge and Pb can improve the ductility of Ni3Sn4.•The relevant electronic structure analysis are discussed.