On some spectroscopic properties of a layered 1,3-diammoniumpropylene tetrabromocadmate hybrid crystal

• Phase transitions in layered compound has been studied by different measurements.
• Wide temperature range vibrational analyses have been done.
• Cationic contribution to the phase transition mechanism was confirmed.
• The two phase transition was evident.

Various techniques of measurements: differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), differential thermal analysis (DTA), infrared (IR), far infrared (FIR) and Raman spectroscopy have been used to investigate the phase transitions in NH3(CH2)3NH3CdBr4 crystal. DSC showed the existence of phase transitions at T1 = 326 K (classified as second-order) and T2 = 368 K (classified as first-order). The IR, FIR and Raman spectra for powered crystal were studied in the wide temperature range. The Raman spectrum has been obtained from the single crystal. Cationic and anionic contribution to the phase transitions mechanism by analysis of the temperature changes of wavenumber, width and intensity of the bands with an assignment of some bands due to internal modes have been proposed and obtained.