| Pb-based ceramics could be used for some practical applications such as high charge storage devices, energy conversion devices and displacement electromechanical actuator. In the last decades, pure and compositionally modified PZ-based ceramics had been widely used for the sake of excellent properties and mature manufacturing process. Phase transition between the antiferroelectric (AFE) and ferroelectric (FE) phases of (Pb1-xBax) ZrO3 (PBZ) ceramics had attracted considerable attention in recent years. In this paper, PBZ ceramics were synthesized by the traditional solid state reaction method, and characterized for their dielectric properties and ferroelectric properties.In this work, ceramic samples of the (Pb1-xBax) ZrO3 (x=0,2.5,5,7.5,10,15,20, 25 and 30 mol%) were prepared by a conventional mixed oxide solid state reaction method. The raw materials of Pb3O4, ZrO2, and BaCO3 were weighed according to the formula (Pb1-xBax) ZrO3, where 0≤x≤0.30, and 0.3%MnO2 was used for sintering aids. Phase transition was investigated by dielectric measurements in the temperature range from 27 to 350℃at various frequencies. The ferroelectric (FE) to paraelectric (PE) phase transition temperature was found to shift to a lower temperature by increasing barium content. The permittivity of the solids corresponding to (Pb1-xBax) ZrO3 (0≤x≤0.30) showed the maximum value of 10220 at x= 0.10 at the phase transition temperature. For compositions 0≤x≤0.10, the antiferroelectric (AFE) to ferroelectric (FE) phase transition was detected. The results indicated that there are two range of Ba2+ content, x< 0.10 and x> 0.10, in which the changes in these properties were substantially different in PBZ ceramics. The ferroelectric hysteresis loop of the PBZ ceramics for x=0.10 was displayed at room temperature and 0.2 Hz, Pr and Ec were 4.8μC/cm2 and 13.6 kV/cm, respectively.In order to better understand the influence mechanism of MnO2 on the PBZ ceramic, the PBZ10 ceramics of the higher Tc were choosed, and (Pbo.9Bao.1) ZrO3-x mol%MnO2 (x=0.1,0.2,0.3,0.4,0.5) ceramics were prepared. The research results showed that MnO2 had a great influence on the dielectric properties of the PBZ10 ceramics. With the increasing of Mn-doped content, the maximum dielectric constant increased, while Tc didn't change much. We got the maximum value of 14214 at x= 0.40 and about 200℃. According to the modified Curie-Weiss law, we got the diffusivity factor of the (Pbo.9Bao.1) ZrO3-xmol%MnO2 ceramics (x=0.1,0.2,0.3, 0.4,0.5) were 1.18,1.08,0.98,1.01 and 0.966, respectively.Moreover, Al2O3 ceramics doping with Y3+ and La3+ had been synthesized by conventional solid state reaction method. The structure, dielectric and thermal conductivity properties of the samples had been measured. The effects of different sintering temperature on the electrical properties of Al2O3-based samples were investigated. The results indicated that all the ceramics had formed to be pure solid solutions. Moreover, peaks were sharp when the samples was sintered at 1500℃. Thermal conductivity of Al2O3 ceramics reached 8.60 W/(m·K). All the ceramics showed temperature-stable dielectric characteristics. Typical dielectric relaxation behavior is observed in Y-and La-doped Al2O3 ceramics, and the mechanism was also analyzed.
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