First-principles study on high-pressure phases and compression properties of gold-bearing intermetallic compounds

Abstract

Compared to elemental Au, Au-based alloys have attracted wide attention for their economy and superior performance stemming from their distinctive physicochemical properties. The study of the structural characterization for alloy materials remains one of the fundamental issues associated with their future applications essentially. In this work, we theoretically explore some typical intermetallic compounds of Au-based alloys under high pressure, which has been an effective means to generate intriguing crystal configurations with unexpected behaviors. Our ab initio simulations find that Fd-3m-AuRb, Fd-3m-AuBa, and Fd-3m-AuLa become stable above ~10 GPa, and Pmmn-AuAl becomes stable above ~20 GPa. Further investigations of their compression behaviors reveal that the bulk moduli of gold-based alloys can be greatly reduced by combining alkali and alkaline earth metals. The present results have unraveled the high-pressure phases of Au-bearing compounds and provide insights for exploring their important compressibility that is strongly relevant to the containing non-gold elements.

Crystal Structures and Electronic Properties of BaAu Compound under High Pressure

“…Among alkaline earth metals, Ba has the lowest electronegativity based on the Pauling scale, which indicates that it is easy to lose electrons and tends to become a cation once its compound forms [ 25 ]. Previous studies [ 26 ] indicate that the BaAu compound was stabilized with Pnma symmetry at atmospheric pressure, which is also theoretically suggested in our recent study [ 27 ]. However, the ground-state Pnma -structured BaAu is still metallic material under ambient conditions [ 28 ].…”

Effect of pressure on the structure transitions and electronic properties of the organic semiconducting Bis(salicylaldehyde) crystal

“…High pressure can change the distance between atoms and the transfer of electrons, resulting in chemical changes [12]. Studying materials' transformation, stability, and superconductivity under high pressure [13][14][15] is essential. Therefore, in this paper, we focus on the structure and properties of bis(salicylaldehyde) crystals under high pressure.…”

Calculation of Mechanical Properties, Electronic Properties, and Thermodynamic Properties of AuAl Crystal: First‐Principles Calculation

“…In recent years, researchers generally apply hydrostatic pressure to effectively improve intermetallic compounds' mechanical properties and anisotropy and obtain high stability and excellent mechanical properties. [12,13,14] Calculated the properties of Co 21 W 18 with increasing hydrostatic pressure. The calculation results showed that the mechanical properties and structural stability of Co 21 W 18 were greatly improved under higher hydrostatic pressure and pointed out the direction for the application of Co 21 W 18 under extreme conditions.…”