Effect of annealing on the dielectric properties of PZN–PT–BT ceramics

The dielectric behaviors of Pb(Zn1/3Nb2/3)O3–PbTiO3–BaTiO3 (PZN–PT–BT) ceramics of several compositions have been systematically studied in as-prepared (unannealed) condition as well as after annealing (at 880 °C for 16 h). The general trend seems to indicate that the annealed samples become more ferroelectric-like as opposed to relaxor type in the unannealed state. It also shows a shift of Tm, the temperature at dielectric maximum, toward higher value after annealing. Both behaviors are composition dependent. X-ray diffraction patterns reveal changes of crystalline structure after annealing, which can be correlated to the accompanied changes in dielectric properties. Those experimental results may be understood using a model of paraelectric BZN nano-phase particles embedded in the PZN–PT–BT matrix.