Electronic structure, optical and vibrational properties of Ti2FeNiSb2 and Ti2Ni2InSb double half heusler alloys

We report the structural, elastic, electronic, optical and vibrational properties of double half Heusler (DHH) compounds Ti2FeNiSb2 and Ti2Ni2InSb within density functional theory (DFT) for the first time. The calculated elastic constants express that both compounds are mechanically stable and show ductile mechanical character. Computed band structures of these compounds indicate typical semiconductor behaviour with the band gap energies of 0.63 eV for Ti2FeNiSb2 and 0.42 eV for Ti2Ni2InSb. We have also searched the optical properties such as the dielectric function, optical conductivity, refractive index, absorption index and reflectance for both compounds. Besides, we have computed vibrational properties i.e. zone-centre Raman and infrared phonon modes along with the phonon dispersion relations and phonon density of states of surveyed compounds.

Automated summary

In this study, the structural, elastic, electronic, optical, and vibrational properties of double half Heusler compounds Ti2FeNiSb2 and Ti2Ni2InSb were investigated using density functional theory for the first time. The calculated results indicate that both compounds are mechanically stable with ductile mechanical character, exhibit semiconductor behavior with band gap energies, and possess specific optical and vibrational properties.