Evolution of domains and thermal hysteresis effects in the pyrochlore-structure ferroelectric Cd2Nb2O7

An analysis of the thermally induced domain behavior in Cd2Nb2O7 under cooling and heating in the dark has revealed that below T-c the coexistence of ferroelectric-ferroelastic domains of different types is accompanied by irreversible changes in the domains of the previous phase (T-c<T< T-s). Interaction of domains with dislocations and other lattice defects causes thermal hysteresis in the phase transition region near T-s and T-c typical of the "superheated'' ferroic state. (C) 1997 American Institute of Physics.