Development of a force-matched embedded-atom method (EAM) potential for rhodium-barium alloy system

An embedded-atom method (EAM) potential for the Rhodium-Barium (Rh-Ba) alloy system has been parameterised. Computational research on the C15 laves phase compound BaRh₂ has been carried out to shape it in critical functional and structural applications. This compound is a type-II superconductor with strong electron–phonon coupling strength. Firstly, the force-matching approach has been used to parameterise the EAM potential, and then the optimisation procedure on converged density-functional theory (DFT) data sets has been carried out to make an appropriate and reliable potential for the Rh-Ba alloy system. A list of fundamental properties, such as density, cohesive energy, elastic properties, thermal expansion coefficient, surface energy, and point defect formation energy, has been examined through molecular dynamics (MD) simulation using the developed EAM potential and validated with DFT-based analysis in order to investigate the accuracy and performance of the potential. A good match between MD and DFT analysis has been found. Thereafter, the EAM potential has been implemented in MD simulation in order to investigate lattice thermal conductivity and diffusional characteristics of the BaRh₂ crystal. Diffusion in the crystal lattice is governed by Rh atoms. Phase stability investigation at different temperatures reveals that the hexagonal BaRh phase is most stable. Besides this, the melting points of the above-mentioned alloy system at different compositions are calculated. Slight deviations in the determination of melting points have been reported. X-ray diffraction (XRD) spectra and radial distribution characteristics of the BaRh₂ crystal have been additionally presented here to provide further insights into the C15 crystal structure.