High performance X8R dielectric ceramics were prepared by dopingBi2O3 to BaTiO3-based ceramics.The effect of small amounts（≤1.2 mol%） ofBi2O3 additive on the microstructure and dielectric properties of BaTiO3-based...High performance X8R dielectric ceramics were prepared by dopingBi2O3 to BaTiO3-based ceramics.The effect of small amounts（≤1.2 mol%） ofBi2O3 additive on the microstructure and dielectric properties of BaTiO3-based ceramics have been investigated.The Bi2O3 ,acting as a sintering additive,can effectively lower the sintering temperature of BaTiO3-based ceramics from 1300 to 1130 °C.The bulk density of BaTiO3-based ceramics increased and reached the maximum value with increasingBi2O3 content.The dielectric constant increased with increasingBi2O3 until it reached the maximum value with 0.8 mol%Bi2O3 additive,and the dielectric loss decreased with increasingBi2O3 content.Optimal dielectric properties of ε=2470,tanδ=0.011 and △ε/ε 25 ≤±9%（-55-150 °C） were obtained for the BaTiO3-based ceramics doped with 0.8 mol%Bi2O3 sintered at 1130 °C for 6 h.展开更多
The Daniels’ barium vacancy layer model of semiconducting BaTiO3 ceramics is analyzed.A grain boundary barrier model with both acceptor states of grain boundary and barium vacancy diffusion layers for the transition ...The Daniels’ barium vacancy layer model of semiconducting BaTiO3 ceramics is analyzed.A grain boundary barrier model with both acceptor states of grain boundary and barium vacancy diffusion layers for the transition from PTC effect to grain boundary barrier layer (GBBL) capacitor is proposed.The proposed model solves the problem occurring in Daniels’ model and makes it possible to calculate physical properties of semiconducting BaTiO3 ceramics and relevant devices.展开更多
基金supported by the Tianjin Natural Science Foundation, China (Grant No. 06YFJMJC01000)
文摘High performance X8R dielectric ceramics were prepared by dopingBi2O3 to BaTiO3-based ceramics.The effect of small amounts（≤1.2 mol%） ofBi2O3 additive on the microstructure and dielectric properties of BaTiO3-based ceramics have been investigated.The Bi2O3 ,acting as a sintering additive,can effectively lower the sintering temperature of BaTiO3-based ceramics from 1300 to 1130 °C.The bulk density of BaTiO3-based ceramics increased and reached the maximum value with increasingBi2O3 content.The dielectric constant increased with increasingBi2O3 until it reached the maximum value with 0.8 mol%Bi2O3 additive,and the dielectric loss decreased with increasingBi2O3 content.Optimal dielectric properties of ε=2470,tanδ=0.011 and △ε/ε 25 ≤±9%（-55-150 °C） were obtained for the BaTiO3-based ceramics doped with 0.8 mol%Bi2O3 sintered at 1130 °C for 6 h.
文摘The Daniels’ barium vacancy layer model of semiconducting BaTiO3 ceramics is analyzed.A grain boundary barrier model with both acceptor states of grain boundary and barium vacancy diffusion layers for the transition from PTC effect to grain boundary barrier layer (GBBL) capacitor is proposed.The proposed model solves the problem occurring in Daniels’ model and makes it possible to calculate physical properties of semiconducting BaTiO3 ceramics and relevant devices.
