Vibrational spectra of magnesia cement, phase 3

Autor: Isao Kanesaka, Shin Aoyama
Rok vydání: 2001
Předmět:
Zdroj: Journal of Raman Spectroscopy. 32:361-367
ISSN: 1097-4555
0377-0486
DOI: 10.1002/jrs.706
Popis: Infrared and Raman spectra of magnesia cement, Mg2(OH)3Cl · 4H2O (phase 3), were observed at room temperature. The formation process of phase 3 was investigated from the change in OH− stretching vibrations by comparison with those of phase 5. Broad infrared bands were observed at ∼1300 cm−1 (H system) and 1050 cm−1 (D system) with some structures in phase 3, which is considered to result from the coupling of the OH stretching vibration with lattice modes. The vibrational analysis was carried out for the lattice vibrations (translational modes) of phase 3, assuming OH− and H2O as the point masses on the basis of the valence force field. The Raman intensity was analyzed by the modified many-body model. The infrared intensity was also analyzed using known parameters, by adding the dipole moments due to electric charges of ions, the orientation of permanent dipoles (OH− and H2O) and induced dipoles by electric charges. The force constants were determined in consistency with the calculated wavenumbers and the calculated infrared and Raman intensities. Copyright © 2001 John Wiley & Sons, Ltd.
Databáze: OpenAIRE
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