Pb (1−x) La x [(Zr 0.6 Ti 0.4 ) (1−x) (Mn 1/3 Sb 2/3 ) x ]O 3 ceramics with x = 0.02, 0.03, 0.04, and 0.05 were synthesized by using a conventional solid state reaction route. The influence of La, Mn, and Sb contents on phase structure, microstructure, and electric properties were investigated. The results of X-ray diffraction (XRD) show that the phase structure of the ceramics transforms from rhombohedral phase to tetragonal phase. However, the minority pyrochlore phase appears on the micrographs of XRD and SEM if the doping concentration is greater than 2 mol%. The grain size of the ceramics gradually increases (from 1.36 µm to 1.57 µm) with increasing doping. The dielectric properties of the ceramics have been measured as a function of temperature in the range of 20°C to 430°C at 1 kHz. The results indicate that the transition temperature and the maximum dielectric constant decrease with increasing PL-PMS content in the system. These results clearly show the significance of PL-PMS in controlling the dielectric behavior of the PL-PMS-PZT system.

The structural and electrical properties of Pb[Zr x Ti 0.95−x (Mo 1/3 In 2/3) 0.05 ]O 3 piezoelectric ceramics system with the composition near the morphotropic phase boundary were investigated as a function of the Zr/Ti ratio. Studies were performed on the samples prepared by the conventional method of thermal synthesis of mixed oxides. The materials structure was investigated by X-ray diffractometry to demonstrate the coexistence of the tetragonal and rhombohedral phases. In the present system, the MPB, in which the tetragonal and rhombohedral phases coexist, is in a composition range of 0.47 ≤ x ≤ 0.50. The lattice constants of the a and c axes for the samples were calculated from the XRD patterns. Microstructure of the sintered ceramics was observed by scanning electron microscopy (SEM) of free surfaces specimens. The relative permittivity, dielectric dissipation, piezoelectric coefficient and electromechanical coupling factor reach at maximum value x = 0.49 (ε r = 7300.345 (at the Curie temperature), tanδ = 0.002050, d 31 = 94.965 PC/N and k p = 0.513 and a Curie temperature of 430˚C). These properties are very promising for applications in ultrasonic motors.

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In this contribution, (0.80-x)Pb(Cr 1/5 ,Ni 1/5 ,Sb 3/5)O 3-xPbTiO 3-0.20PbZrO 3 perovskite ceramics namely PZT-CNS were prepared by solid state reaction method. The obtained samples have been characterized by different techniques including XRD, density test, SEM analysis, and Dielectric measurements in order to investigate the effects of sintering temperature and titanium content on microstructure and dielectric properties. The obtained experimental results have been reported and well discussed.

Perovskite PZT variants were synthesized from stoichiometric oxide ratios of Pb, Zr, Ti, Cr, Ni and Sb. The oxide powders were mixed mechanically and calcinated, and then sintered to form the desired perovskite phase. The detailed structural and ferroelectric properties were carried out for sintered specimens. The results of X-ray diffraction showed that all the ceramics specimens have a perovskite phase. The multi-component ceramic system consists of the (0.80 − x)Pb(Cr 1/5 ,Ni 1/5 ,Sb 3/5)O 3-xPbTiO 3-0.20PbZrO 3 (PZT-CNS), with 0.30 ≤ x ≤ 0.42, and the ternary system near the rhombohedral/tetragonal morphotropic phase boundary(MPB) was investigated by X-ray diffraction and dielectric properties. In the present system, the MPB that coexists with the tetragonal and rhombohedral phases is a narrow composition region of x = 0.38-0.42. The scanning Electron Microscopy (SEM) showed an increase of the mean grain size when the sintering temperature was increased. A sintered density of 92.93% of the theoretical density was obtained for Ti = 42% after sintering at 1180˚C. Ceramics sintered at 1180˚C with Ti = 42% achieve excellent dielectric properties, which are as follows ε r = 4262.48, and Tc = 340˚C.