Pressure-Induced Phase Transition and Electronic Structure Changes in Equiatomic FeV
Classical molecular dynamics methods can accurately describe a broad set of many-atomssystems. Although more economical, the results given by this framework lack the precisioncapable of density functional theory (DFT). Therefore, the structural stability ofthe B2 phase of a body-centered-cubic iron-vanadium (FeV) alloy using DFT on the electronicstructure level is analyzed to verify and further explain classical results obtainedby our group in this same alloy. Using Quantum Espresso and Phonopy for the computationalsimulations, the plotted band structure, electronic density of states (eDOS), phonondispersions, charge density, and Fermi surfaces for various compressed unit cells are presented.The results obtained with PBE and PBEsol pseudopotentials show similarities intheir trends. However, the predicted parameters do not match, as seen in the high-pressurephase transition, which is different by 20 GPa between PBE and PBEsol. The eDOS andband structure display shiftings at the Fermi energy, meaning more electrons are available toscreen the ions' movement. A comparison between density functional perturbation theory(DFPT) and DFT results is made, and although the predicted outcome coincides, the waythe transitions appear differs from one another. Furthermore, the transition consequencein the electrons is presented as a redistribution of charge in the second nearest neighbors ofvanadiums in the interstitial sites which may have a role explaining the difference betweenthe pressure predicted by DFT and the available experimental results at lower vanadiumconcentrations.
Condensed matter physics|Materials science|Physics
Reyes Pulido, Homero, "Pressure-Induced Phase Transition and Electronic Structure Changes in Equiatomic FeV" (2022). ETD Collection for University of Texas, El Paso. AAI29321986.