The thermoreflectance of YIG single crystals was measured in the visible energy range. Spectra of this compound support a model that incorporates both localised and one-electron band states. All structures of the thermoreflectance spectra exhibit temperature dependence. Those at low energies, which occur at 16390, 17220, 19321, 20350, 21450, 22410, 23609 and 24271 cm-1 and exhibit a small temperature shift and broadening, were assigned to crystal-field-split localised interionic transitions between the 3d states of Fe3+. The other structures, occurring at 25775, 27367, 30453, 32500, 35248, 39514 and 44202 cm-1 with a considerable temperature shift (between 2*10-3 and 8*10-4 eV K-1) and broadening were ascribed to pair transitions between the 3d states of iron and/or to charge-transfer transitions involving delocalised valence-band oxygen states and iron d-like bands.
Balzarotti, A., Picozzi, P., Ricchiuto, A., Santucci, S. (1979). Thermoreflectance studies of yttrium-iron garnet crystals, 12(23), 5233-5243 [10.1088/0022-3719/12/23/027].
Thermoreflectance studies of yttrium-iron garnet crystals
BALZAROTTI, ADALBERTO;
1979-01-01
Abstract
The thermoreflectance of YIG single crystals was measured in the visible energy range. Spectra of this compound support a model that incorporates both localised and one-electron band states. All structures of the thermoreflectance spectra exhibit temperature dependence. Those at low energies, which occur at 16390, 17220, 19321, 20350, 21450, 22410, 23609 and 24271 cm-1 and exhibit a small temperature shift and broadening, were assigned to crystal-field-split localised interionic transitions between the 3d states of Fe3+. The other structures, occurring at 25775, 27367, 30453, 32500, 35248, 39514 and 44202 cm-1 with a considerable temperature shift (between 2*10-3 and 8*10-4 eV K-1) and broadening were ascribed to pair transitions between the 3d states of iron and/or to charge-transfer transitions involving delocalised valence-band oxygen states and iron d-like bands.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.