ABSTRACT
Relaxor and ferroelectric materials are outstanding for electronic application, indicating kind of ferroelectric material is still ambiguously due to different behavior of stoichiometric ratio of precursors. The samples of 0.94Pb(Fe1/2Nb1/2)O3-0.06PbTiO3 (PFNT94/6) and 0.9Pb(Fe1/2Nb1/2)O3-0.1PbTiO3 (PFNT90/10) were mixed with ZnO at 0, 1, 2, and 3 wt.%, and were synthesized using mixed oxide. Phase transition and microstructure were analyzed by using X–ray diffractometer (XRD) and SEM technique, respectively. The results showed that PFNT94/6-xZnO and PFNT90/10-xZnO shifted to tetragonal phase and suppressed pyrochlore phase when increasing ZnO content. Grain size decreased with increasing ZnO contents in range of 0.89–2.18 µm of PFNT94/6 due to coarsening processes dominate, the production of a highly porous is easily be found and decreased the average grain size, conversely, grain size increased with increasing ZnO contents in range of 3.15–11.52 µm of PFNT90/10. The PFNT94/6 exhibits broaden peak of dielectric constant, meanwhile, the dielectric constant maximum temperature at 144°C of PFNT90/10. The dispersion of dielectric constant decreases with increasing ZnO contents. The relaxor ferroelectric of PFNT90/10 ceramic shifted to normal ferroelectric with increasing ZnO contents. Ferroelectric properties were investigated on polarization electric field, polarization of PFNT94/6 exhibited relaxor ferroelectric at low field, PFNT90/10 showed normal ferroelectric as well as endurable breakdown. The relaxor ferroelectric material can be modified to ferroelectric material by adding ZnO.
Acknowledgments
The authors are grateful to School of Ceramic Engineering, Institute of Engineering, Suranaree University of Technology, Nakhon Ratchasima Thailand for providing measurement facility and introducing technique of analyzing electrical properties.