Insight into the mechanical, electronic, kinetic, thermodynamic, and hydrogen storage properties of XFeH 3 (X = Ca, Sr, Ba) perovskites for hydrogen storage applications: First-principle calculations

Based on the first -principle calculations, the XFeH 3 (X =Ca, Sr, Ba) hydrides have been systematically investigated. The lattice constant, elastic constants, bulk modulus, Poisson ' s ratio, and Young ' s modulus of XFeH 3 hydrides are calculated. According to the B/G and Poisson ' s ratio, CaFeH 3 and SrFeH 3 exhibit brittleness, while BaFeH 3 exhibits ductility. The electronic properties demonstrate that CaFeH 3 and SrFeH 3 exhibit half -metallic ferromagnetism, while BaFeH 3 exhibits metallic ferromagnetism. We analyze the Bader partial net charges to better understand the charge transport in XFeH 3 hydrides. In addition, the formation energy, Born stability criterion, and phonon dispersion curves of XFeH 3 were investigated, which confirmed that XFeH 3 perovskites are simultaneously thermodynamic, mechanical, and kinetic stable. The gravimetric hydrogen storage capacities of CaFeH 3 , SrFeH 3 , and BaFeH 3 are 3.06, 2.06, and 1.54 wt%, respectively, revealing that CaFeH 3 hydride can be a better material for hydrogen storage applications compared to SrFeH 3 and BaFeH 3 . Our results would provide a new candidate for hydrogen storage materials.