Neutron diffraction analysis on a possible disordered structure of paraelectric rochelle salt

Neutron diffraction refinement of paraelectric structure of deuterated Rochelle salt at 40 °C and −195 °C was performed. Existence of large anisotropic thermal motions suggests a possibility of disordered structure with small atomic shifts. Split atom method was applied and a disordered structure model for the paraelectric phase was proposed. Phase transition based on this model was discussed.