First-principles studies on mechanical, thermodynamic and electrical properties of AgAuPd medium entropy alloy

Abstract:

Ag bonding wires are widely applied to the field of microelectronic packaging because of their good electrical properties. However, pure Ag wires possess the disadvantages of low strength and high temperature failure, and can not be used in high power devices. Therefore, we try to design an equal atomic AgAuPd medium entropy alloy as new bonding material to replace pure Ag wires. In this work, based on the SQS model, the crystal structure of AgAuPd medium entropy alloy is established. The elastic properties (elastic constants, elastic modulus, shear modulus), thermodynamic properties and electronic structure of AgAuPd medium entropy alloy under different pressures are calculated by first principle. It can be predicted that AgAuPd medium entropy alloy has good structural stability, good plasticity, high temperature stability and good conductivity with increasing of pressure. AgAuPd medium entropy alloy has great potential to become a bonding material. Through using the first principle to calculate the mechanical, thermodynamic and electrical properties of AgAuPd medium entropy alloy under different pressure, it has certain theoretical significance for the development of new Ag base bonding wires.

Key words:medium entropy alloy; first principle; elastic property; SQS model