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Raman scattering spectra of La 3 Ga 5 SiO 14 (LGS) crystals
Author(s) -
Lu G. W.,
Li C. X.,
Wang W. C.,
Wang Z. H.,
Wang Z. M.,
Yuan D. R.,
Xia H. R.
Publication year - 2004
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.200301922
Subject(s) - raman spectroscopy , raman scattering , polarizability , crystal (programming language) , density functional theory , molecular vibration , crystal structure , anisotropy , polar , molecular physics , materials science , scattering , crystallography , chemistry , optics , molecule , computational chemistry , physics , organic chemistry , astronomy , computer science , programming language
Based on the space group theory, the normal vibration modes of La 3 Ga 5 SiO 14 (LGS) crystal were predicted, and the Raman scattering intensities of non‐polar and polar modes were calculated respectively. The lattice vibration and structure of LGS crystal were investigated by Raman spectroscopy and density‐functional theory (DFT). The DFT calculations were made on SiO 4 , GaO 4 , GaO 6 , La 3 Ga 4 O 12 and La 3 Ga 3 SiO 12 clusters, which model the atomic cluster in LGS crystal. Excellent agreement has been achieved between vibrational frequencies predicted by the theory and those observed in experiments. The layer structure of LGS crystal is identified, and its excellent piezoelectric properties are mainly attributed to the large polarizability anisotropy of La 3 Ga 4 O 12 and La 3 Ga 3 SiO 12 clusters, which results from the strong interaction between Ga(Si)O 4 tetrahedras of LGS crystal. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)