Finite pseudo block spin model of ferroelectrics

Abstract

ABSTRACTWe herein explain the phase of ferroelectrics by reference to finite block spin theory, in which the phase of ferroelectrics may be considered as being a ferroelectric ordering between pseudo block spins comprised of random pseudo spins, that is, dipoles that have a majority of individual spins in a given sense. By making use of the Curie-Weiss law of pseudo block spins for ferroelectrics, we obtained the susceptibility for the lower and higher temperature approximations of the Brillouin function. According to our viewpoint, the state of dipole glass can be regarded as paraelectric ordering of pseudo block spins with higher temperature limit and lower temperature limit of the Brillouin function. For Rochelle salts, this phase may have ferroelectric and dipole glass mixed states where higher temperature limit and lower temperature limit and in the intermediate range between these a ferroelectric state happens.