Ferroelectricity of Inclusion Compounds of Thiourea with Pyridinium Iodide and Nitrate

International audienceThe character of phase transitions in the inclusion compounds of thiourea with pyridinium iodide and nitrate has been analyzed, and a model of ferroelectricity of these compounds has been proposed. Analysis of the temperature dependence of specific heat and intensity of the Bragg peaks has shown that the ferro-paraelectric phase transitions are continuous, in contrast to the nonferroelectric phase transitions. The ferroelectricity of the inclusion systems studied is of the mixed type and has a displacement component and an order−disorder component