Investigation of structural, electronic and lattice dynamical properties of XNiH3 (X = Li, Na and K) perovskite type hydrides and their hydrogen storage applications

摘要: Abstract XNiH3 (X = Li, Na, and K) perovskite type hydrides have been studied by using Density Functional Theory (DFT) these materials are found to be stable synthesizable. The X-ray diffraction patterns obtained they indicate that all the polycrystalline structure. electronic properties investigated it has structures show metallic character. Bader partial charge analysis also performed. In addition, elastic constants calculated mechanically stable. Using constants, mechanical such as bulk modulus, shear Poisson's ratio obtained. Moreover, Debye temperatures thermal conductivities studied. anisotropic visualized in three dimensions (3D) for Young's linear compressibility, modulus well with calculation of factors. Additionally, dynamical stability phonon dispersion curves dynamically Also, including free energy, enthalpy, entropy heat capacity hydrogen storage examined gravimetric capacities 4.40 wt%, 3.57 wt% 3.30 wt% LiNiH3, NaNiH3 KNiH3, respectively. Furthermore, desorption 446.3 K, 419.5 K 367.5 K