A DFT investigation on structural, electronic, magnetic, optical, elastic and hydrogen storage properties of Ru-based hydride-perovskites XRuH3 (X = Cr, V, Ni)

Abstract

The present investigation delves into various physical properties exhibited by CrRuH₃, VRuH₃ and NiRuH₃. Notably adopting a stable cubic configuration, both compounds manifest a distinct metallic demeanor characterized by an absolute absence of band gap. In-depth analysis through Total Density of States (TDOS) and Partial Density of States (PDOS) justify this metallic conduct by distinctly showcasing peak conductivity at the Fermi level. The materials' magnetic behavior reveals an antiferromagnetic disposition for CrRuH₃ and NiRuH₃, while their intrinsic attributes emerge as anisotropic and rigid. Applying Poisson's ratio (ν) and the B/G ratio, all investigated compounds show ductility, but the CrRuH₃ is superior among them. The heightened values of Young's modulus, Bulk modulus, and mean shear modulus observed in CrRuH₃ underscore its enhanced rigidity as compared to VRuH₃ and NiRuH₃. Within the optical realm, CrRuH₃ displays notable optical conductivity and absorption, particularly within the lower energy spectrum. Remarkably, at 0 eV, CrRuH₃ showcases elevated reflectivity and refractive index as compared to the other investigated materials. On the hydrogen storage front, XRuH₃ (X = Cr, V, Ni) exhibit promising potential, yet CrRuH₃ emerges as the more favorable candidate for hydrogen storage applications.