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

Abstract

This work shows the influence of admixture on the basic properties of the multicomponent PbZr1−xTixO3 (PZT)-type ceramics. It presents the results of four compositions of PZT-type material with the general chemical formula, Pb0.99M0.01((Zr0.49Ti0.51)0.95Mn0.021Sb0.016W0.013)0.9975O3, where, in the M position, a donor admixture was introduced, i.e., samarium (Sm3+), gadolinium (Gd3+), dysprosium (Dy3+) or lanthanum (La3+). 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 W6+ (at positions B) and M3+ = Sm3+, Gd3+, Dy3+, and La3+ (at positions A) increase the dielectric and piezoelectric properties, while the acceptor dopant Sb3+ (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.

A Combination of Calcination and the Spark Plasma Sintering Method in Multiferroic Ceramic Composite Technology: Effects of Process Temperature and Dwell Time

“…The diffused nature of the phase transition in the perovskite-type materials can increase due to the non-uniform element distribution in the units cell of the crystal structure [ 35 ]. This may be related to the appearance of composition fluctuations (a disturbance in the distribution of ions at the B site in the perovskite unit cell), causing the occurrence of micro-areas with different local Curie temperatures [ 36 , 37 ]. The various admixtures can also induce the formation of non-identical units cell, and the diffused nature of the phase transition can arise due to the coexistence of two different phases in the samples over a wide range of temperatures [ 38 ].…”

Electrophysical properties of the multiferroic PFN–ferrite composites obtained by spark plasma sintering and classical technology

“…The diffuse phase transition occurring in ceramic materials with perovskite structure depends on various factors, for example, chemical composition fluctuations or cation crystallographic site disordering, leading to a microscopic heterogeneity in the composition (are formed microareas as the centers of new phase with different local Curie points) as well as the heterogeneous defect distribution and mechanical stress in the ceramic grains [45]. Lowering the value of electric permittivity and increasing diffuse phase transition of the PFN-F composite obtained in the SPS method may be associated with too fast dynamics of the ongoing process, which causes the heterogeneity of defect distribution and mechanical stress in the ceramic grains.…”

Electrophysical Properties of PZT-Type Ceramics Obtained by Two Sintering Methods

“…These advanced techniques allow for better control of the sintering process and also provide the ability to produce PZT-type ceramics with high microstructure uniformity and higher density. The selection of the appropriate method of sintering PZT ceramics and the optimization of sintering parameters are crucial to obtaining the desired quality and properties of the ceramic material [33][34][35][36][37][38][39][40]. In the technological process, depending on the application, PZT-type materials are obtained, e.g., in the bulk form (as ceramic material), thin or thick layers, gradient materials, and recently even use some 3D printing technologies such as selective laser sintering (SLS), binder jetting (BJT), stereo-lithography (SLA), and material extrusion (MEX) [41].…”