Figure - available from: Journal of Physics: Condensed Matter
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Crystal structures of typical Au-based alloys at 100 GPa. (a) Fd-3m-AuRb, (b) Fd-3m-AuBa, (c) Pmmn-AuAl, (d) P4/nmm-AuFe, and (e) Fd-3m-AuLa. The golden spheres represent Au atoms, and the other colored spheres represent the corresponding elements.
Source publication
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...
Citations
... 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. ...
The structure, electronic, and optical properties of bis(salicylaldehyde) crystal under 0-300 GPa pressure are calculated by density functional theory (DFT). By comparing the lattice parameters (i.e., lattice constants, bond lengths, and bond angles) under different pressures, it is found that the lattice parameters are sensitive to pressure and change complicatedly with pressure. Furthermore, the analysis of the electronic structure shows that the crystal is an indirect bandgap semiconductor at 0 GPa and becomes a conductor at 115, 155, and 185 GPa, respectively, where the far- and near-Fermi levels density of states (DOS) in the valence band are mainly contributed by the O-2s orbital electrons, the joint effect of the C-2p and the O-2p orbital electrons respectively. Dielectric function studies have shown that it exhibits novel optical properties as the pressure increases, leading to different photoelectric properties.
... 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]. ...
The investigations of Au-bearing alloy materials have been of broad research interest as their relevant features exhibit significant advantages compared with pure Au. Here, we extensively investigate the compression behaviors of BaAu compounds via first-principles calculations and find that a high-pressure cubic phase is calculated to be stable above 12 GPa. Further electronic calculations indicate that despite the low electronegativity of Ba, Fd-3m-structured BaAu exhibits metallic characteristics, which is different from those of semiconducting alkali metal aurides that possess slight characteristics of an ionic compound. These findings provide a step toward a further understanding of the electronic properties of BaAu compounds and provide key insight for exploring the other Au-bearing alloy materials under extreme conditions.
The structural stability, elastic properties, electronic properties, and thermodynamic property (Debye temperature) of AuAl intermetallic compound (IMC) are systematically investigated using first‐principles calculations based on density functional theory. The elastic constants, elastic moduli (including bulk modulus, shear modulus, Young's modulus, and Poisson's ratio) and Vickers hardness, the density of states, and Debye temperature of AuAl under hydrostatic pressure are calculated. The calculation results show that AuAl is an elastic anisotropic material with low rigidity and high toughness under zero pressure. Under hydrostatic pressure, the anisotropy index decreases while the hardness and Debye temperature increase. The research in this paper provides a theoretical basis for the study of the properties of bonding gold wire intermetallics.
