A Phenomenological Approach to Phase Transition Temperatures of Pb(Zr,Ti)O3-BiFeO3 System

A phenomenological approach to explain the change of phase transition temperatures (T-C) of Pb(Zr,Ti)O-3-BiFeO3 (PZT-BF) mixed system was proposed. By introducing coupling terms independent of composition together with the averaged free energy terms, the change of T-C was well explained in PbTiO3-BiFeO3 (PT-BF) mixed system. From the parameters obtained from PT-BF system of a(1) and a(11) in Landau-Devonshire theory, we could explain the change of T-C in PZT-BF system in tetragonal phase.