Abstract
Chemical processing of Nb2O5-added BaTiO3 composites was investigated with the surface modification through the hydrolysis of niobium alkoxide on the surface of BaTiO3 particles.
BaTiO3 particles were coated with niobium hydroxide particles formed by preferential hydrolysis of niobium pentaethoxide on the surfaces of BaTiO3 particles, which can lead to the preparation of highly homogeneous composite particles of Nb2O5BaTiO3.
It was clarified from the BET measurement, the SEM&TEM observation and Zeta-potential measurment that original BaTi03 particles were homogeneously coated with niobium hydroxide particles.
Iwt%Nb2O5-added BaTiO3 bodies sintered at 1250-1300°C exhibited a flattened dielectric temperature dependence (dielectric constants of 2200 to 2400) with lower loss(tan δ<1.0%) in the temperature range of -30 to 80°C, indicating a relaxor characteristics. The microstructure of Nb2O5-added BaTiO3 sintered bodies consisted of grains of several μ m which are much smaller than ones of non-added BaTiO3 sintered bodies, suggesting that the grain growth of BaTiO3 was inhibited by niobium existing at the grain boundaries.
