Ferroelectricity and phase transitions INH2(UO2)2(AsO4)2·8H2O

Dielectric behaviour studies have been carried out on H2(UO2)2(AsO4)2·8H2O single crystals. The first member of a new family of ferroelectric and antiferroelectric materials. The crystal shows two phase transitions: above room temperature it behaves as a dielectric with small losses (paraelectric phase), between room temperatures and -20°C it behaves as an antiferroelectric material (showing domain, structure) and below -20°C it is ferroelectric. Once the crystal has become ferroelectric it can be heated up to 30°C and remains for some time in a ferroelectric state.