Investigation of self-consistent site-dependent DFT + U effect on electronic band structure and optical properties of SiFe₂O₄ spinel

Abstract

The first-principle investigation of SiFe 2 O 4 (SFO) spinel was performed with the help of a plane-wave pseudopotential technique within the generalized gradient approximation (GGA) and local density approximation (LDA) as implemented in Quantum Espresso Simulation package. The Electronic band structure and optical properties of SFO spinel-type material have been investigated and discussed in this paper. The calculated band structure reveals that SFO spinel-type material is a direct bandgap semiconductor. Using GGA+U and LDA+U the band gap value so obtained is 3.52 eV and 2.96 eV respectively. The contribution to valence and conduction bands due to different bands was analyzed on the basis of the total and partial density of state. The Optical properties of SFO spinel-type material have been calculated and discussed in detail. The real, e w 1 ( ) and the imaginary, e w 2 ( ) part of the complex dielectric constants is found to be 6.52 and 5.42 at energies of 3.44 eV and 6.21 eV respectively. The refractive index n 0 ( ) and the reflectivity index w R , ( ( )) at zero energy value were found to be 1.88 and 10% respectively. We found that SFO spinel-type material has good properties for optical devices.

Topotactic transformation of gadolinite‐ to melilite‐type structure revisited

“…The comparison of experimental and theoretically predicted phonon vibrational frequencies is demonstrated in Table S11. Theoretical modeling of iron‐containing minerals presents challenges due to the need to take into account possible electron correlation effects 69 . These effects can also affect the obtained phonon frequencies, as well as Raman intensities 70 .…”

“…Theoretical modeling of ironcontaining minerals presents challenges due to the need to take into account possible electron correlation effects. 69 These effects can also affect the obtained phonon frequencies, as well as Raman intensities. 70 Besides, the presence of absorption including in the near-infrared region was noticed for a number of iron-containing minerals and ironcontaining glasses (e.g., Refs.…”

Systematic investigation of magneto-electronic, structural, thermoelectric and optical properties of Nd2MgX4 (X = S, Se) compounds

“…The first part consists of the interstitial region whose potential is increased with the help of plane wave orbitals while second part consists of the muffin tin region. Local density of approximation (LDA + U) was used in the investigations [11]. BoltzTraP code is used to compute TE parameters for Nd 2 MgX 4 (X = S, Se) by employing the rigid band approximation (RBA) and constant scattering time approximation (CSTA).…”