Vibrational spectrum of nasicon-like, rhombohedral orthophosphates M IM IV2(PO 4) 3
Abstract
The Raman and i.r. spectra of nasicon-type M IM IV2(PO 4) 3 rhombohedral phosphates (M I = Li, Na, K, Rb, Cs, Tl; M IV = Ge, Sn, Ti, Zr, Hf) exhibit intricate relationships between the spectra and the chemical composition. The pattern of the PO 4 stretching frequencies is more or less strongly modified by the nature of both M IV and M I cations. Still greater variations are observed in the medium and low frequency region, although some external modes have been identified by the study of mass effects ( 6Li 7Li, 70Ge 76Ge, ZrHf etc.). The origin of this complex behaviour is discussed in relation to the structure.
- Publication:
-
Spectrochimica Acta Part A: Molecular Spectroscopy
- Pub Date:
- 1986
- DOI:
- 10.1016/0584-8539(86)80012-5
- Bibcode:
- 1986AcSpA..42.1009T