Transverse and longitudinal crystal modes associated with OH stretching vibrations in single crystals of kaolinite and dickite |
| |
Authors: | Farmer V C |
| |
Institution: | Macaulay Land Use Research Institute, Craigiebuckler, Aberdeen, UK. c.farmer@mluri.sari.ac.uk |
| |
Abstract: | Raman spectra of randomly-oriented kaolinite, dickite and nacrite show, for coarsely crystalline material, an extra band in the OH stretching region which is absent from the IR spectra of clay-size samples. Oriented single-crystal Raman spectra of these minerals provide confirmation for the assignment of the extra bands to transverse optical modes involving in-phase coupled vibrations of the layer-surface hydroxyl groups. The corresponding IR bands have transition moments nearly perpendicular to the layer surface, and appear at the higher frequencies of the longitudinal optical modes of macroscopic crystals. |
| |
Keywords: | |
本文献已被 ScienceDirect PubMed 等数据库收录! |
|