Raman scattering investigation of the phase transitions in (NH4)2ZnBr4

Abstract
Results of Raman spectroscopic studies of (NH4)2ZnBr4 crystal in the spectral range from 20–250 cm−1 and over a range of temperature from 90K to 440K covering the low temperature ferroelectric and high temperature incommensurate phases are presented. The plots of the integrated areas and peak heights of the strong Raman lines versus temperature show anomalous behaviour near the two phase transitions.