Premium
The significance of anti‐fluorite Cs 2 NbI 6 via its structural, electronic, magnetic, optical and thermoelectric properties
Author(s) -
Ullah Rehan,
Ali Malak Azmat,
Murtaza G.,
Mahmood Asif,
Ramay Shahid M.
Publication year - 2020
Publication title -
international journal of energy research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.808
H-Index - 95
eISSN - 1099-114X
pISSN - 0363-907X
DOI - 10.1002/er.5638
Subject(s) - thermoelectric effect , condensed matter physics , magnetism , magnetic moment , materials science , figure of merit , ground state , ferromagnetism , magnetic semiconductor , semiconductor , band gap , density functional theory , chemistry , optoelectronics , atomic physics , physics , computational chemistry , thermodynamics
Summary The structural, electronic, magnetic, optical and thermoelectric properties of anti‐fluorite Cs 2 NbI 6 were investigated using full potential augmented plane wave method of density functional theory. Structurally, Cs 2 NbI 6 was found to be cubic in ground state from values of tolerance factor (1.04) and formation energy (−22.3 eV). While, it's ferromagnetic nature was predicted from volume optimization process. In spin down channel, the compound was explored as indirect band gap (E g(Γ‐X) = 1.97 eV) semiconductor, while it changes to metallic in upper spin channel. Nb‐ d and I‐ p states were exposed as the main cause of spin dependent electronic nature (half‐metallicity). The origin of magnetism in Cs 2 NbI 6 was explained on basis of crystal field theory. The calculated magnetic moment (1.001 μ B ) was found in reasonable agreement with experimental value. The optimum absorption and optical conductivity spectra in semiconductor state explored Cs 2 NbI 6 as suitable for optoelectronic devices. Furthermore, the transport properties were calculated using BoltzTrap code. The nature of carriers was predicted as n type from negative values of Seebeck coefficients. Where, the figure of merit (ZT) was found to increase up to 0.85 at 900 K. The present work not only explores Cs 2 NbI 6 as potential optoelectronic and thermoelectric material, but can also inspire more experimental research on this important compound.