Abstract: The Morse parameters were calculated using experimental values for the energy of vaporization, the lattice constant, and the compressibility. The equation of state and the elastic constants which were computed using the Morse parameters, agreed with experiment for both face-centered and body-centered cubic metals. All stability conditions were also satisfied for both the face-centered and the body-centered metals. This shows that the Morse function can be applied validly to problems involving any type of deformation of the cubic metals.

Abstract: An embedded-atom method (EAM) potential for the Pd-Ba alloy system has been developed in order to forward computational research in this alloying system as there is no EAM potential available for this alloy system. The force-matching method has been implemented to develop the EAM potential first, and then, optimisation to converged density-functional theory (DFT) data sets has been done to generate the accurate and reliable potential for the Pd-Ba alloy system. Some physical, elastic and thermal properties of BaPd₂ crystal have been calculated through molecular dynamics (MD) simulation using the developed EAM potential and then verified these properties with the help of DFT analysis in order to examine the performance of the potential. The presence of some even peaks of BaPd₂ in virtual XRD spectra using MD simulation has been justified by DFT analysis. Slight deviations in melting points calculation at different compositions of the Pd-Ba alloy system have been observed. Higher Ba-Pd interaction using radial distribution characteristics and slower kinetics for inter-diffusion through diffusional characteristics study of BaPd₂ have been reported using MD simulation with the developed EAM potential. In spite of some discrepancies due to deficiency in the potential, a closer agreement between MD and DFT analysis has been observed.

Abstract: Platinum-barium (Pt-Ba) alloy cathodes are promising for magnetron amplifiers due to their high electron emission coefficient and excellent work function. High-temperature deformation characteristics have the utmost importance with respect to these types of metal alloy cathodes. Molecular dynamics (MD) simulations have been carried out to study tensile and creep deformation characteristics of a single crystal BaPt₂ compound using a parameterized embedded-atom method (EAM) potential. The force-matching methodology and an optimization approach using converged density-functional theory (DFT) datasets have been used in this work to parameterize an EAM potential for the Pt-Ba alloy system. A list of fundamental properties, such as density, cohesive energy, and elastic properties, has been investigated via MD simulation, and these properties have been verified with the help of DFT analysis to examine the performance of the potential. Tensile deformation characteristics have been carried out at different temperatures from 300 K to 1600 K for strain rates of 10⁸/s, 10⁹/s, 10¹⁰/s, and 10¹¹/s. Ductile characteristics have been found, as supported by Pugh's criterion. In addition, creep characteristics have been studied at different loads ranging from 100 MPa to 400 MPa for temperatures 0.3 T_m, 0.6 T_m, and 0.8 T_m (i.e., T_m is the melting temperature), where no tertiary region has been observed. Additionally, X-ray diffraction spectra and radial distribution characteristics have also been visualized through MD simulation.

Abstract: The unavailability of embedded-atom method (EAM) potential for the Platinum-Barium (Pt-Ba) alloy system, which is an enticing choice as cathodes for magnetron amplifiers due to their high electron emission coefficient and excellent work function. The parameterization of an EAM potential for this alloy system has been described in part 1 portion. Studying different deformation mechanisms is crucial for these kinds of alloy systems in order to implement them in critical engineering applications. Tensile and creep characteristics have already been reported in part 1, along with the validation of density, cohesive energy, and elastic properties. Here, a list of other fundamental properties, such as lattice constant, surface energy, and lattice thermal conductivity, have been investigated via molecular dynamics (MD) simulation and compared with density-functional theory (DFT) analysis to concretize the accuracy of the potential. Thereafter, MD simulation has been used to study the deformation behavior of single crystal BaPt₂ compound under asymmetric cyclic loading having "R" (stress ratio) of -0.2, -0.4, and -0.6 at different temperatures ranging from 300 K to 1600 K using the parameterized EAM potential. A constant strain rate of 10⁸/s has been used in this present study. Although variations in strain axis are not significant, an increase in ratcheting strain with the increment in temperature and an increase in strain accumulation with the decrease in magnitude of stress ratio have been observed. Strain amplitude decreases and stabilizes at a terminal value, as observed from the strain cycle plot.

Abstract: 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.