Domain Contribution to Dielectric Properties of Fine-Grained BaTiO3 Ceramics
Domain Contribution to Dielectric Properties of Fine-Grained BaTiO3 Ceramics
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DOI：
10.1143/jjap.48.09kc01
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发表时间：
2009-09
影响因子：
1.5
通讯作者：
T. Hoshina;Yoichi Kigoshi;S. Hatta;H. Takeda;T. Tsurumi
中科院分区：
文献类型：
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作者：
T. Hoshina;Yoichi Kigoshi;S. Hatta;H. Takeda;T. Tsurumi
采用常规烧结法、两步烧结法和速率控制两步烧结法制备了不同粒度的纯BaTiO 3陶瓷。当晶粒尺寸大于1.1 μm时，陶瓷的介电常数随晶粒尺寸的减小而增大;当晶粒尺寸小于1 μm时，陶瓷的介电常数随晶粒尺寸的减小而减小。场发射扫描电子显微镜（FE-SEM）观察表明，BaTiO 3晶粒中的畴大多为简单的片层结构，90°畴宽随晶粒尺寸减小而减小。通过超宽范围介电谱，研究了畴对介电常数的贡献。对于晶粒尺寸大于1 μm的BaTiO 3陶瓷，高畴密度增强了偶极子和离子极化率。相反，对于晶粒尺寸小于1 μm的BaTiO 3陶瓷，这些极化率被削弱。
Pure BaTiO3 ceramics with various grain sizes were prepared by a conventional sintering method, a two-step sintering method, and a rate-controlled two-step sintering method. The permittivity of the ceramics increased with decreasing grain size when the grain size was more than 1.1 µm, while that decreased when the grain size was below 1 µm. Field emission scanning electron microscopy (FE-SEM) observations revealed that most of the domains in BaTiO3 grains had simple lamellar structures, and 90° domain width decreased with decreasing grain size. By ultrawide range dielectric spectroscopy, the domain contribution to the permittivity was investigated. For the BaTiO3 ceramics with grain sizes over 1 µm, the dipole and ionic polarizabilities were enhanced by the high domain density. In contrast, for the BaTiO3 ceramics with grain sizes below 1 µm, these polarizabilities were weakened.