Theoretical characterization of quaternary iridium based hydrides NaAeIrH6 (Ae = Ca, Ba and Sr)

• NaAeIrH6 (Ae = Ca, Ba and Sr) alloys have been investigated.
• The elastic moduli, energy gaps are predicted.
• The optical and thermal properties were studied.

The quaternary iridium based hydrides NaAeIrH6 (Ae = Ca, Ba and Sr) are promising candidates as hydrogen storage materials. We have studied the structural, elastic, electronic, optical and thermodynamic properties of NaAeIrH6 (Ae = Ca, Ba and Sr) within the generalized gradient approximation, the local density approximation (LDA) and mBj in the frame of density functional perturbation theory. These alloys have a large indirect Γ–X band gap. The thermodynamic functions were computed using the phonon density of states. The origin of the possible transitions from valence band to conduction band was illustrated. By using the complex dielectric function, the optical properties such as absorption, reflectivity, loss function, refractive index and optical conductivity have been obtained.

Real and imaginary parts of the dielectric function, the absorption spectrum α(ω), reflectivity R(ω) and energy-loss spectrum L(ω).Figure optionsDownload as PowerPoint slide