Effect of sintering temperature on boundary segregation and dielectric properties of (Ba,Nb)-doped TiO2 ceramics

[[abstract]]The effect of sintering temperature on the boundary segregation and dielectric properties of several (Ba,Nb)-doped TiO2 ceramics was investigated. Koops equations are used to explain the dispersive dielectric properties and to study the boundary segregation. Calculated results of the thickness of the boundary segregation layer are presented, and its variation with sintering temperature and dopants is also discussed. Increasing sintering temperature generally increased the grain size of samples which consequently increased the relative dielectric constant. However, there was significant abnormal grain growth in samples doped with 0.25 mol.% Nb and 0.80 mol.% Ba and sintered at an intermediate temperature of about 1250°C. This resulted in the highest relative dielectric constant observed in the investigation. The thickness of the segregation layer increased with sintering temperature for compositions doped with barium, whereas it decreased for compositions doped without barium. This is attributed to either plastic or electrostatic interactions[[fileno]]2020301010026[[department]]材料科學工程學