Microstructure and dielectric properties of PMN-PT ceramics prepared by the molten salts method

The sintering characteristic and dielectric properties of 0.67PMN-0.33PT ceramics prepared by the molten salt synthesis (MSS) method were investigated. PMN-PT particles synthesized by MSS with smaller grain size and good dispersion could lower the sintering temperature of ceramics; PMN-PT ceramics with relative density above 96% could be obtained in the range 1150-1180 degrees C. The molten salts species could significantly affect the microstructure and proper-ties of MPN-PT ceramics. In the range 1100-1200 degrees C, PMN-PT ceramics from the sulfate flux MSS powders showed intergranular fracture, but that from the chloride flux MSS powder showed transgranular fracture. At the same sintering condition, the properties of PMN-PT ceramics from the powders prepared in the chloride flux are better than that from the powders prepared in the sulfate flux, their maximum dielectric constant epsilon(max)approximate to 29,385 and piezoelectric constant d(33)approximate to 660 pC/N. The above results demonstrated that PMN-PT ceramics prepared by the molten salts method possessed excellent piezoelectric and dielectric properties. (C) 2009 Elsevier Ltd. All rights reserved.