Far-infrared spectra of ammonium layer and framework silicates
Mookherjee, Mainak; Redfern, Simon A.T.; Zhang, Ming
published: Jan 16, 2004
The low-temperature behaviour of the ammonium mica: synthetic ND4-tobelite and ND4-phlogopite has been studied by infrared spectroscopy in the far infrared region, from room temperature down to 20 K. Unlike previously studied low-temperature, orientational ordering of the ammonium ion in the inter-layer region from the near infrared region (Mookherjee et al. 2002 a, b), the bands in far infrared region do not show significant change on cooling. This indicates that the coupling between ordering of ammonium ions and other structural rearrangements is weak.