Compositional Studies and Electrical Properties of the Leadbased Relaxor Solid Solutions

Lead-based relaxor ceramics are ferroelectric materials exhibiting excellent dielectric and piezoelectric behavior. These materials are used in a wide range of devices such as capacitors, sensors, actuators and transducers. To achieve high performance, the pure perovskite structure must be obtained. However, it is difficult to avoid the presence of a pyrochlore phase that causes degradation of both dielectric and piezoelectric properties. The present work focuses on the influence of various parameters such as the amount of a stabilizer (PbTiO3, PT), calcination and sintering conditions on the stability of perovskite structure and electrical properties. Three systems, PMN-PT, PZN-PT and PNN-PT, prepared by the Columbite precursor method, were investigated. The maximum permittivities at room temperature for PMN, PZN and PNN were obtained in the PMN-PT 95/5, PZN-PT 85/15, and PNN-PT 75/25 compositions, respectively. Meanwhile, the maximum remanent polarizations for PMN, PZN and PNN were obtained in the PMN-PT 65/35, PZN-PT 85/15 and PNN-PT 65/35 compositions.