No ferroelectricity in semicarbazide hydrochloride and its deuterated crystals

A high precision neutron diffraction structural analysis, dielectric, spontaneous polarisation and optical absorption studies have been carried out to understand the two unusually close ferroelectric phase transition1 at 19°C and 21°C of hydrated and deuterated semicarbazide hydrochloride single crystals. No anomally could be observed in any of the above experiments. Effect of ionising radiation (x-ray or γ-ray) on the dielectric, optical and thermal expansion properties of the crystals were studied and discussed. All these measurements indicate that these crystals are not ferroelectric.

Keywords:

• Ferroelectric phase transition
• space group
• dielectric anomally and neutron diffraction