The dependence of the synthesis condition on the dielectric behaviors of the 0.75Pb(Fe_2/3W_1/3)O₃-0.25PbTiO₃ based ceramics

In this paper, 0.75Pb(Fe_2/3W_1/3)O₃-0.25PbTiO₃-0.15 wt%MnO (0.75PFW-0.25PT-0.15 wt%MO) ceramics are synthesized by combining the conventional direct oxide synthesized (DS) method and the indirect synthesized (IS) method. Due to the IS method, the lattice structure and the grain structure of the 0.75PFW-0.25PT-0.15 wt%MO ceramics are changed. Furthermore, the low-field dielectric responses are evidently modified such as follows: (1) the broad dielectric peak becomes sharper; (2) in the paraelectric region, the space charge polarization is eliminated; (3) the frequency dispersion of the dielectric constant is suppressed; (4) the dielectric loss is effectively decreased in both the ferroelectric and paraelectric regions. In conclusion, the dielectric characteristics of the 0.75PFW-0.25PT-0.15 wt%MO ceramics synthesized by the IS method are trend to the long range order (LRO) ferroelectric behaviors.