Effect of metal atoms on the superconducting properties of decahydrides, MH10 (M = Ga, Nb & Mo)

Highlights: • Electronegativity difference of metal with respect to hydrogen atom tunes the H–H distances in these hydrides. • NbH₁₀ shows highest DOS(~2.62 states/eV/f.u.) at the Fermi level. • Decahydrides NbH₁₀, GaH₁₀ and MoH₁₀ are predicted to be room temperature superconductors above 150 GPa. • A new methodology have been developed to calculate e-Ph coupling parameter (λ) and ω_log in this manuscript. Applying first principles calculations we have explored the effect of metal atoms on the superconducting properties of decahydrides of Gallium (Ga), Niobium (Nb) and Molybdenum (Mo) at 150 GPa. These atoms owing to their apt electronegativities, metallic radii and other physical parameters stabilise the host guest type clathrate structure of decahydrides. Our calculations show the highest density of state (DOS) (N(E_F) = 2.62 states/eV/f.u.) at the Fermi level for NbH₁₀ along with presence of van Hove singularity among all decahydrides. This N(E_F) value is ~163% enhanced compared to that of LaH₁₀ at 150 GPa making it a sought for high T_C material. Our correlative analysis establishes a pivotal role for chemical properties, in particular, electronegativity of metal atoms in tuning the H–H distances and hence the superconductivity of decahydrides.