First principle study of structural, electronic, magnetic, optical and thermal properties of chalcogenides XFeSe₂ (X = Li, Na and K) half metallic compounds

Abstract

Half-metallic ferromagnets (HMF) are one of the most essential materials for spintronics. The electronic, magnetic, optical and transport properties of hexagonal XFeSe2 (X = Li, Na and K) compounds have been investigated by Wien2K code. The Heisenberg classical model has been used to determine spin polarization. The ferromagnetism is confirmed by the negative exchange energy Δx (pd), exchange constants, and quantum interchange of electrons in strong p-d hybridization. The integer values of total magnetic moment (MT) of 5.0000 µB, 4.9995 µB, and 5.0000 µB per formula unit has further verified the HMF in LiFeSe2, NaFeSe2 and KFeSe2 respectively. Optical properties reveal that the absorption of light energy exist in visible to ultraviolet regions. Moreover, refective index, reflectivity spectrum and optical conductivity are also reported. Lastly, BoltzTraP code was used to explore the influence of electrical and thermal conductivities of electrons spin, potential gradient effect and figure of merit (ZT). Results reveal that the studied compounds are potential candidates for spintronic devices and other energy applications.

Cu-based novel transition-metals chalcogenides for advanced optoelectronic and thermoelectric devices: first-principles study

“…[1][2][3][4][5][6][7][8]. In addition to the experimental study, these material groups are also the subject of extensive theoretical research [9,10]. For covering the associations in-between crystal structures and optical nature, computational research employing ab-initio quantum mechanical calculations has become crucial.…”