**3.1. Microstructure**

Figure 4 shows SEM micrographs of the surface of the PLZT(7/65/35) and PLZT(9.1/65/35) ceramics sintered at 1225°C. Densely packed microstructures of both ceramics are observed. In the sintering temperature range between 1225°C and 1275°C, the grain growth was not remarkable for these samples; however, the surface roughening were observed in the ceramics sintered at 1275°C, suggesting the lead evaporation loss from the samples. Figure 5 shows SEM micrographs of the surface of the BaTiO3 ceramics sintered at 1300°C, 1350°C, and 1400°C. The surface of the BaTiO3 ceramics sintered at 1300°C consists of the small grains of 1–2 μm. The melted grains are observed in the BaTiO3 ceramics sintered at 1350°C, and large grains at 50– 200 μm grains were observed in the BaTiO3 ceramics sintered at 1400°C. This suggests the abrupt grain growth happened in the sintering temperature above 1350°C.

**Figure 4.** SEM micrographs of the surface of the PLZT(7/65/35) and PLZT(9.1/65/35) ceramics sintered at 1225°C.

Fig. 4
