Abstract
We report the first measurements of FIR and MIR reflectivity of single-crystal monoclinic antiferromagnetic copper monoxide (CuO) in a wide temperature range (7-300 K) when b-axis and ac-plane polarized modes are completely separated and excited in transverse geometry. Previously reported softening of the A(u)(3) mode at the NC el transition is confirmed and found to be up to two times more significant (about 10%). For the first time an emergence of several new IR-active lines at low temperatures is observed. The highest frequency new mode at 690 cm(-1) strongly hardens and strengthens with cooling. The data are discussed in terms of strong spin-phonon coupling and possible charge disproportionation at low T. (C) 2000 Elsevier Science B.V. All rights reserved.
| Original language | English |
|---|---|
| Pages (from-to) | 1396-1397 |
| Number of pages | 2 |
| Journal | Physica B: Condensed Matter |
| Volume | 284 |
| Publication status | Published - Jul-2000 |
| Event | 22nd International Conference on Low Temperature Physics - HELSINKI, Finland Duration: 4-Aug-1999 → 11-Aug-1999 |
Keywords
- charge disproportionation
- infrared spectroscopy
- magnetic ordering
- spin-phonon interaction