Abstract
Optical spectra of a single crystal of (Formula presented)(Formula presented)(Formula presented), which undergoes a charge-ordering transition at (Formula presented)∼240 K, have been investigated for wide ranges of photon energy (0.008-3 eV) and temperature (10-480 K). The opening of a charge gap as well as change of the gap magnitude (2Δ) with temperature is clearly observed below (Formula presented), with an anomalously large ratio of 2Δ(T=0)/(Formula presented)(Formula presented) (∼13). Conspicuous spectral change with temperature is also observed above (Formula presented) over the energy region up to 2 eV, which suggests persistent fluctuation of the charge ordering or formation of small polarons above (Formula presented).
| Original language | English |
|---|---|
| Pages (from-to) | R14230-R14233 |
| Journal | Physical Review B - Condensed Matter and Materials Physics |
| Volume | 54 |
| Issue number | 20 |
| DOIs | |
| Publication status | Published - 1996 Jan 1 |
| Externally published | Yes |
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics