Optical phonon modes and transmissivity in BaWO4 single crystal
β Scribed by Donggang Ran; Hairui Xia; Shangqian Sun; Peng Zhao; Fengqin Liu; Zongcheng Ling; Wenwei Ge; Huaijin Zhang; Jiyang Wang
- Publisher
- John Wiley and Sons
- Year
- 2006
- Tongue
- English
- Weight
- 193 KB
- Volume
- 41
- Category
- Article
- ISSN
- 0232-1300
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β¦ Synopsis
Abstract
Barium tungstate (BaWO~4~) single crystal has been grown using Czochralski technique. It belongs to the scheelite structure, forming the space group I 4~1~/a at room temperature and the primitive cell contains two molecular units. The polarized Raman spectra were recorded by a microβRaman spectrophotometer system in the backscattering geometry. All the observed Raman modes were assigned. The Raman mode at 924 cm^β1^, which belongs to the totally symmetrical A~g~ optical modes, has the strongest intensity and its linewidth is 4.6 cm^β1^. The infrared active lattice vibrations have been studied, eight optical modes were observed and assigned. The ultraviolet absorption edge is at 256 nm and the optical transparency range is up to 2500 nm at room temperature. The energy gap E~g~ of this crystal was obtained from the optical transmission spectra. (Β© 2006 WILEYβVCH Verlag GmbH & Co. KGaA, Weinheim)
π SIMILAR VOLUMES
Raman measurements on ZnSe/GaAs heterostructures show unusual behaviour of the optical phonon modes from ZnSe. High epitaxy rates are responsible for both poor structural quality at the interface and Fermi level pinning by carrier traps. The Γrst e β ect gives rise, beyond a critical thickness, to po