Abstract
The electronic structures and optical properties of zinc chromite, ZnCr2O4, were calculated using the density-functional theory within the local-spin-density approximation (LSDA), the LSDA plus Hubbard-like parameter U, LSDA+U, and the spin-polarized generalized-gradient approximation. ZnCr2O4 was found to be a direct-band-gap semiconductor with an optical band gap of 2.9 eV, with the uppermost valence bands (lowermost conduction bands) having mainly Cr-t2g (Cr-eg) characteristics. The calculated band gap using LSDA+U showed better agreement with the available experimental data than previous calculations. The optical-conductivity and the reflectivity spectra were also calculated. The calculated reflectivity spectrum exhibited two peaks, one at ~3.5 eV and the other at ~5.8 eV, which were assigned to the electronic interband transitions from the O-2p to the Cr-3d states and from the O-2p derived bands to the Cr eg bands, respectively.
Original language | English (US) |
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Pages (from-to) | 1233-1237 |
Number of pages | 5 |
Journal | Journal of the Korean Physical Society |
Volume | 57 |
Issue number | 5 |
DOIs | |
State | Published - Nov 15 2010 |
Keywords
- Density-functional calculations
- Electronic structures
- LSDA+U
- Optical properties
- Oxide spinels
ASJC Scopus subject areas
- General Physics and Astronomy