Research of the structural, electronic, and mechanical properties of new palladium-based sulfosalts under high pressure

Abstract

Pressure is a fundamental thermodynamic variable that can be used to modify the properties of materials because it reduces the interatomic distances and modifies the electronic orbitals and the connection patterns of the sample. It is a versatile tool for creating exotic materials not accessible in environmental conditions. Recently, high-pressure experimental techniques developed have led to the synthesis of new functional materials with excellent performance: for example, superconductors, superhard materials, and high energy density materials. Computer simulations aided and accelerated some of these advances, an essential tool for the search for crystalline structures and the characterization of physical properties. Thus, this work investigated the structural, electronic, and mechanical properties of the Roterbärite family (PdCuBiX3 - X = S, Se or Te) under the influence of high pressure through Density Functional Theory (DFT) calculations using the Quantum Espresso. The calculations have been performed using Perdew–Zunger’s LDA (LDA-PZ) exchange-correlation (XC) functional. The crystal structure has been computationally optimized under several pressures, and the bulk modulus was found to be 71,65 GPa, 53,02 GPa, and 50,3 GPa for the PdCuBiS3, PdCuBiSe3 and PdCuBiTe3 respectively. Electronic structure calculations demonstrated that PdCuBiS3 and PdCuBiSe3 are semiconductors, and PdCuBiTe3 is metallic.