Prediction and Analysis of Crystal Structure, Mechanical Properties, High-temperature Performance and Electronic Characteristics of Pt-5Au-xZr alloys: First-Principles Calculations

Pt-Au alloys have attracted attention as promising candidates for next-generation platinum channels due to their cost-effectiveness and enhanced performance on glass substrates. The addition of trace amounts of Zr is expected to improve chemical stability and tune key properties such as strength and conductivity. To examine the influence of Zr concentration, density functional theory was used to study the structural, thermal, and electronic properties of Pt-5Au-xZr alloys with Zr contents ranging from 0.0 to 5.0 wt%. The results show that Zr addition effectively improves the stability of Pt-5Au-xZr crystals. Regarding mechanical properties, the toughness of Pt-5Au-xZr alloys initially increases and then decreases with added Zr, while hardness exhibits an opposite trend. Notably, at 2.0 wt% Zr, the Pugh’s ratio peaks at 5.197 GPa and hardness reaches its lowest value of 2.215 GPa. Regarding high-temperature performance, Pt-5Au-2.0Zr exhibits excellent stability. At 1600 K, its thermal expansion coefficient is measured to be 3.60 × 10-5·K-1. DOS analysis confirms that Zr incorporation modifies the electronic states near the Fermi level: at moderate contents, electronic delocalization lowers the dislocation slip barrier, while excessive contents induce partial localization, strengthening rigidity but reducing ductility. Consequently, Pt-5Au-2.0Zr achieves an optimal balance of toughness and high-temperature stability. This study provides a comprehensive analysis of different Zr contents on the performance of Pt-5Au alloys, delivering important theoretical guidance for their potential engineering applications.