Presented as part of a commemorative issue for Wolfgang Kiefer on the occasion of his 65th birthday.
Vibrational spectra of synthetic crandallite-type minerals—optical and inelastic neutron scattering spectra†
Article first published online: 12 JAN 2006
Copyright © 2006 John Wiley & Sons, Ltd.
Journal of Raman Spectroscopy
Special Issue: Commemorative Issue: for Wolfgang Kiefer on the Occasion of his 65th Birthday
Volume 37, Issue 1-3, pages 208–216, January - March 2006
How to Cite
Breitinger, D. K., Brehm, G., Mohr, J., Colognesi, D., Parker, S. F., Stolle, A., Pimpl, Th. H. and Schwab, R. G. (2006), Vibrational spectra of synthetic crandallite-type minerals—optical and inelastic neutron scattering spectra. J. Raman Spectrosc., 37: 208–216. doi: 10.1002/jrs.1444
- Issue published online: 12 JAN 2006
- Article first published online: 12 JAN 2006
- Manuscript Accepted: 24 AUG 2005
- Manuscript Received: 27 MAY 2005
- Deutsche Forschungsgemeinschaft. Grant Number: Br 422/23-1+2.
- Fonds der Chemischen Industrie.
- Universitätsbund Erlangen-Nürnberg.
- crandallite-type minerals;
- vibrational spectra;
- inelastic neutron scattering;
- disorder effects;
- perturbed symmetry
The vibrational spectra of the synthetic minerals crandallite and goyazite MAl3(OH)6(HPO4)(PO4) (M = Ca and Sr) were studied by means of vibrational (IR and Raman) and inelastic neutron scattering (INS) spectrometries at room and low temperatures. The results were discussed taking into consideration the effects of different types of disorder (random distribution of PO4 and HPO4, orientational distribution with HPO4 and displacement of Ca in crandallite). The consequences of the resulting perturbed symmetry and of the non-equivalence of the bridging µ-OH groups in the Al2OH fragments were pointed out (complexity of the ν(Al2OH), δ(Al2OH) and γ(Al2OH) bands). The vibrations of the PO4 and HPO4 groups could be separated. Some aspects of the vibrational behaviour of the AlO2(OH)4 units and of the layers composed therewith were addressed. The translational modes of the interlayer cations Ca2+ and Sr2+ could be observed; the findings support the suggested displacement of Ca in crandallite. Copyright © 2006 John Wiley & Sons, Ltd.