Structural, electronics, magnetic, optical, mechanical and hydrogen storage properties of Ga-based hydride-perovskites XGaH3 (X = K, Li)

The present study investigates some physical properties of KGaH3 and LiGaH3 whose lattice parameters and band gap match well with a previous study involving Ga-based hydride-perovskites. Both the compounds are found to be stable in cubic form and have a metallic character with zero band gap. The TDOS and PDOS confirm the metallic behavior by showing maximum conductivity at the Fermi level. Both materials are found antiferromagnetic, anisotropic and hard in nature. KGaH3 is found brittle and LiGaH3 is found ductile according to Poisson's ratio v. The brittleness in KGaH3 and the ductility in LiGaH3 is also verified by the B/G ratio. The high value of Bulk modulus, young modulus, and mean shear modulus for LiGaH3 show that it is harder than KGaH3. A high optical conductivity and absorption is found in both materials in the lower energy regime. At 0 eV, LiGaH3 possesses high value of reflectivity and refractive index than KGaH3. The hydrogen storage properties show that both materials are capable for storing hydrogen, however, LiGaH3 is found a preferred material for hydrogen storage applications. Novelty Statement The structural, electronics, magnetic, optical, mechanical and hydrogen storage properties of Ga-based hydride-perovskites XGaH3 (X = K, Li) are studied for the first time in the present study. There is no theoretical or experimental literature available for these compounds.

Automated summary

This study investigates the physical properties of KGaH3 and LiGaH3, including lattice parameters, band gap, magnetic behavior, mechanical properties, and optical properties. The compounds are found to be stable cubic metallic materials with antiferromagnetic behavior and anisotropic properties. LiGaH3 exhibits better mechanical and hydrogen storage properties, making it a preferred material for hydrogen storage applications.