The Effect of Mixed Doping on the Microstructure and Electrophysical Parameters of the Multicomponent PZT-Type Ceramics

This work shows the influence of admixture on the basic properties of the multicomponent PbZr(1−x)Ti(x)O(3) (PZT)-type ceramics. It presents the results of four compositions of PZT-type material with the general chemical formula, Pb(0.99)M(0.01)((Zr(0.49)Ti(0.51))(0.95)Mn(0.021)Sb(0.016)W(0.013))(0.9975)O(3), where, in the M position, a donor admixture was introduced, i.e., samarium (Sm(3+)), gadolinium (Gd(3+)), dysprosium (Dy(3+)) or lanthanum (La(3+)). The compositions of the PZT-type ceramics were obtained through the classic ceramic method, as a result of the synthesis of simple oxides. The X-ray diffraction (XRD) pattern studies showed that the obtained multicomponent PZT materials have a tetragonal structure with a P4mm point group. The microstructure of the obtained compositions is characterized by a well crystallized grain, with clearly visible grain boundaries. The composition with the admixture of lanthanum has the highest uniformity of fine grain microstructure, which positively affects its final dielectric and piezoelectric properties. In the multicomponent PZT-type ceramic, materials utilize the mixed (acceptor and donor) doping of the main compound. This dopiong method has a positive effect on the set of the electrophysical parameters of ceramic materials. Donor dopants W(6+) (at positions B) and M(3+) = Sm(3+), Gd(3+), Dy(3+), and La(3+) (at positions A) increase the dielectric and piezoelectric properties, while the acceptor dopant Sb(3+) (at positions B) increases the time and temperature stability of the electrophysical parameters. In addition, the suitable selection of the set of admixtures improved the sinterability of the ceramic samples, as well as resulted in obtaining the required material with good piezoelectric parameters for the poling process. This research confirms that all ceramic compositions have a set of parameters suitable for applications in micromechatronics, for example, as actuators, piezoelectric transducers, and precision microswitches.