The microstructure and dielectric properties of a solid solution (1-x)K0.5Bi0.5TiO3 - xSrTiO(3) for x=0.001 ceramics

The paper presents the results of measurements of a solid solution (1-x)K0.5Bi0.5TiO3-xSrTiO(3) (KBT-ST) ceramics for x=0.001 with two different sintering temperatures: (1) at temperature 1303 K for 6 hours (KBT-ST 1) and (2) at temperature 1313 K for 6 hours (KBT-ST 2). In both cases, the X-ray diffraction study demonstrated the perovskite structure with a small amount of the second phase. Microstructure research with SEM allowed to observe well-developed grains for both obtained samples. Optical studies using Raman spectroscopy showed that the obtained samples have a local structure consistent with the base material K0.5Bi0.5TiO3 (KBT). Dielectric study of these solid solution ceramics were taken in the temperature range from 293 K to 873 K and in the frequency range from 10 kHz to 1 MHz. These measurements allowed to observe in both cases a broad maximum similar to that for the base KBT ceramics. It has been observed that if the sintering temperature increase up to 1313 K it causes a double increase in the dielectric constant and the appearance of additional anomaly on the epsilon(T) curve at temperature approximately T-d=521 K.