Baochun Guo

Effect of Preparation Methods on Microstructures and Microwave Dielectric Properties of CdWO4 Ceramics

The monoclinic structure (p2/c) CdWO4 compound was synthesized by high energy ball mill (HEBM), conventional solid state (CSS) and reaction-sintering (RS) methods. The influence of the processing method on the characteristics of CdWO4powders and the related microwave dielectric properties for sintering ceramics was investigated. The results indicate that the HEBM method is an effective way for preparing fine powders and reduces the calcining or sintering temperatures, RS method was simplified greatly. Due to the very different nature of the powders and sintering temperature, the ceramics by CSS and RS showed very strong orientation growth. The CSS method ceramics have a higher density and better microwave dielectric properties than HEBM or RS method, and the variation of Qf, ϵr and τf werealso explained based on the difference in microstructures.

Effect of Ti content on energy storage properties of (Pb0.87Ba0.10La0.02)(Zr0.60Sn0.40-xTix)O3 bulk ceramics

ABSTRACT (Pb0.87Ba0.10La0.02)(Zr0.60Sn0.40-xTix)O3(PLBZST) (x = 0–0.20) bulk ceramics were prepared by the conventional solid state method, and the dependence of phase transformation, ferroelectric properties and energy storage properties on x values has been investigated. When x = 0.12, the unit cell volume significant change indicted the phase transformation of the ceramics. As x = 0.04–0.10, the PLBZST ceramics possess anti-ferroelectric phase with high recoverable energy storage density 0.8–1.3 j/cm3 and when x = 0.12–0.20, the ceramics with ferroelectric phase have lower density values about 0.2–0.3 j/cm3. The phase switching electric field, saturation polarization and test temperature have an important influence on energy storage density and efficiency. As a result, the PLBZST bulk ceramics exhibit the largest recoverable energy density of 1.3 j/cm3 with efficiency of 77.4% at 20°C.