Ferroelectric-like transition on a hygroscopic barium thiourea chloride single crystal

Abstract

Barium thiourea chloride (BTC) single crystals were grown by slow evaporation of aqueous solution. The X-ray and spectral studies confirmed the formation of the title compound. Thermal studies carried out using differential scanning calorimetry (DSC) showed the presence of both the adsorbed and absorbed water in the grown crystal, which can be identified through the peaks around temperatures 80°C and 130°C. The dielectric constant against temperature curve for different frequencies showed concomitant anomaly around the temperature region of 80°C to 120°C similar to a ferroelectric phase transition. We infer that this peak is due to the removal of water and not due to ferroelectric transition and care should be taken while measuring and interpreting dielectric properties of similar hygroscopic crystals containing volatile compounds.