Infrared optical constants of ferroelectric triglycine fluoberyllate

Abstract

Transmission and reflection spectra of triglycine fluoberyllate are investigated at different temperatures (80-355K) from 20 to 4000 cm-1. Optical and electrical constants are calculated. The temperature dependence of the two lowest-frequency bands is examined in terms of Lorentz oscillators. The internal vibrations nu 3 and nu 4 of the two BeF4 ions of the unit cell can be unambiguously assigned because there are no other vibrations (C-H, N-H, C-C, ...) in this region of the spectrum.