First-Principle Calculation of Structural, Mechanical, Electronic and Magnetic Properties of Cobalt Sub Hydrides Co2H and Co3H

In this present work, we perform first-principles calculations of the structural, electronic, mechanical and mechanical properties of Cobalt sub-hydrides (Co2H and Co3H) based on the density functional theory with local spin density (LSDA), and generalized gradient (GGA) approximations. The optimized structural parameters, densities of states, elastic constants (Cij) and mechanical properties (Young’s modulus Y, Shear modulus G, Poisson’s ratio ν) were obtained for the first time and analyzed. Our calculation shows that the insertion of hydrogen in low-concentration into cobalt leads to the expansion of unit cell volume and the bulk modulus as a function of this concentration. A resulting strong reduction of magnetization characterizes these subs-hydrides.