Effect of the composition and sintering process on the electrical properties in Pb(Mg1/3Nb2/3)O3-PbTiO3 ceramics

The effects of the composition and the sintering process on the ferroelectric, dielectric and electromechanical properties in (1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 ceramics with 0.1 less than or equal to x less than or equal to 0.4 were investigated. It was found that the densification process was strongly dependent on the amount of PT. For the lowest concentration of PT the microstructure of the both hot-pressed and conventional sintered samples were very similar, reflecting in almost identical electrical properties. Nevertheless, it was noticed that the higher amount of PT higher was the deviation of the electrical properties between the conventional and the hot-pressed samples. The gradual decreasing of the physical properties of the conventional sintered ceramics was related to the gradual decrease of the density and inhomogeneous microstructure. The results also revealed that for the lower concentration of lead titanate a relaxor behavior is noticed with a high electrostrictive effect, which was almost hysteretic free. However, higher amount of lead titanate led to a "normal" ferroelectric behavior. (C) 2003 Elsevier Ltd. All rights reserved.