Sintering and Dielectric Properties of BaTiO3-Ni Composite Ceramics
Sintering and Dielectric Properties of BaTiO3-Ni Composite Ceramics
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DOI：
10.2109/jcersj.100.555
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发表时间：
1992-04
影响因子：
1.1
通讯作者：
H. Emoto;J. Hojo
中科院分区：
文献类型：
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作者：
H. Emoto;J. Hojo
在1300°C下，分别在氩气和空气中对BaTiO 3-Ni混合粉末进行烧结，研究其烧结行为和介电性能。烧结体的体积密度为理论值的95-99%。在Ar气氛中制备了BaTiO_3-Ni复合材料。当使用粗Ni粉（4-7μm）和超细BaTiO_3粉（0.02μm）时，大量Ni颗粒孤立地分散在BaTiO_3基体中。根据修正的麦克斯韦公式，当Ni含量为40vol%时，介电常数ε r ′=11000。在Ar气氛中烧结的BaTiO_3由于氧空位的形成而具有较高的介电损耗，而BaTiO_3-Ni复合材料具有较低的介电损耗。这是因为少量NiO溶解在BaTiO_3中，Ni离子作为电子受体补偿了氧空位的电荷。在空气中烧成导致Ni的氧化，形成具有低介电常数和高介电损耗的BaTiO 3-NiO复合材料。
BaTiO3-Ni mixed powders were sintered at 1300°C in Ar or air, and the sintering behavior and dielectric properties were investigated. The bulk density of sintered bodies was 95-99% of theoretical. BaTiO3-Ni composites were produced in Ar. When coarse Ni powder (4-7μm) and ultrafine BaTiO3 powder (0.02μm) were used, a large number of Ni particles were isolatedly dispersed in the BaTiO3 matrix. The dielectric constant increased remarkably with an increase in Ni content up to er′=11000 at 40vol% Ni according to the modified Maxwell formula. Although monolithic BaTiO3 sintered in Ar had a high dielectric loss owing to the formation of oxygen vacancies working as electron donor, BaTiO3-Ni composite had a low dielectric loss. This is because of the fact that a small amount of NiO dissolved into BaTiO3 and Ni ions worked as electron acceptor to compensate the charge of oxygen vacancies. Firing in air resulted in the oxidation of Ni to form BaTiO3-NiO composites with low dielectric constants and high dielectric losses.