Abstract
Two kinds of lead-based relaxor materials which are different in sintering temperature, (Pb, Sr) (Mg, Zn, Nb, Ti)O3 [H-material] and Pb(Zn, Nb, Fe, W)O3 [L-material], for multilayer ceramic capacitor were synthesized from oxide powders by calcination at 1170°C and 800°C in H-material and L-material, respectively. Each material was ground by ball-milling into two kinds of powders with different particle size [H (C), L (C), H (F) and L (F) powder], respectively. Average particle sizes of H (C), L (C), H (F) and L (F) powders were 0.73, 1.31, 0.25 and 0.22μm, respectively. These four kinds of powders were mixed in four kinds of conbination of H (C)-L (C), H (F)-L (C), H (C)-L (F) and H (F)-L (F) with various ratios. Microstructure and dielectric properties of ceramics sintered from their mixed powders were experimentally investigated focusing on the 2-phase structure of H-and L-material. The densification of their mixed powders was mainly dependent on the particle size of L-material. The densification of H (F)-L (F) powder was achieved at the lowest temperature in four kinds of mixed powder, and dense ceramics were obtained from H (F)-L (F) powder with a ratio of 1 : 2 at firing temperature of 900°C. It was concluded, that the microstructure consists partially of 2-phase structure of H-and L-materials. (from the SEM observation and their dielectric properties)
