A lead-free bulk ceramic having a chemical formula Ba0.8Ca0.2(Ti0.8Zr0.1Ce0.1)O3 (further termed as BCTZCO) is synthesized using mixed oxide route. The structural, dielectric, impedance, and conductivity properties, as well as the modulus of the synthesized sample are discussed in the present work. Analysis of X-ray diffraction data obtained at room temperature reveals the existence of some impurity phases. The natural surface morphology shows close packing of grains with few voids. Attempts have been made to study the (a) effect of microstructures containing grains, grain boundaries, and electrodes on impedance and capacitive characteristics, (b) relationship between properties and crystal structure, and (c) nature of the relaxation mechanism of the prepared samples. The relationship between the structure and physical properties is established. The frequency and temperature dependence of the dielectric properties reveal that this complex system has a high dielectric constant and low tangent loss. An analysis of impedance and related parameters illuminates the contributions of grains. The activation energy is determined for only the high temperature region in the temperature dependent AC conductivity graph. Deviation from the Debye behavior is seen in the Nyquist plot at different temperatures. The relaxation mechanism and the electrical transport properties in the sample are investigated with the help of various spectroscopic (i.e., dielectric, modulus, and impedance) techniques. This lead free sample will serve as a base for device engineering.

본 실험에서는 낮은 음의 온도계수를 갖는 저온 소결 유전체에 대해 연구하였다. 새로 개발된 재료의 조성은 TiO2(100-X) CuOx(X=1~5wt%)에 미량의 MnO2를 첨가 하였다. CuO를 첨가하지 않은 경우에는 저온 (900˚C) 에서 소결이 진행되지 않았다. CuO 함량이 증가할수록 저온에서 소결이 가능하였으나, 유전율이 낮아지고 유전손실은 증가 하였다. MnO2를 0.6wt% 첨가한 경우 유전율과 Q값이 가장 높게 나타났다.