Synthesis, growth and thermal and Fourier transform infrared spectral characterization of tetraethylammonium tetrachloro manganate (II) monohydrate crystals

Abstract

Single crystals of a novel tetraethylammonium tetrachloro manganate (II) monohydrate (TEATC-Mn) were grown by slow evaporation solution technique at room temperature. These crystals belong to a class of interesting ferroelectric materials. The grown crystals were characterized through powder X-ray diffraction (XRD), thermogravimetry, differential thermal analysis (TG-DTA), differential scanning calorimetry (DSC) studies and Fourier transform infrared (FTIR) spectra. While the results of the elemental analysis of the compound agree with the stoichiometry, its crystallinity is confirmed by the powder X-ray diffraction pattern. The weight losses observed were suitably explained based on the formulated decomposition pattern. The differential thermal analysis of the compound conforms to the thermogravimetric study. The endothermic peak observed in the high temperature differential scanning calorimetry suggests the occurrence of a phase transition in the compound between 300 and 370 °C while the corresponding low temperature study shows thermal anomalies at −41.7, −51.7 and at −52.4 °C. This suggests the occurrence of both first and second order phase transitions. The characteristic absorptions in the FTIR spectrum further characterize the compound. Further investigations on the ferroelectric behaviour of the compound at low temperatures are in progress.