Progress in Research on Critical Size of Phase Transition in Ferroelectrics

Theoretical approaches(such as macroscopic thermodynamics phenomenological approach, microscopic transverse field Ising model and first-principles calculation)in dealing with size effect and predicts on critical size of ferroelectric phase transition are reviewed from two aspects,ferroelectric film and ferroelectric grain,respectively.Critical sizes of some ferroelectrics observed in experiments are summarized from 1950s.Some size effects of ferroelectric ceramics are introduced simply.Ferroelectric phase transitions of ferroelectric nanowires reported recently are narrated too.Finally,some problems in researching progress are pointed out.