Nanometer silicon carbide powder synthesis and its dielectric behavior in the GHz range
Nanometer silicon carbide powder synthesis and its dielectric behavior in the GHz range
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DOI：
10.1016/s0955-2219(01)00248-5
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发表时间：
2002
影响因子：
5.7
通讯作者：
Bo Zhang;Jian-bao Li;Jingjing Sun;Shuxia Zhang;H. Zhai;Zhengwei Du
中科院分区：
文献类型：
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作者：
Bo Zhang;Jian-bao Li;Jingjing Sun;Shuxia Zhang;H. Zhai;Zhengwei Du
本文研究了纳米SiC粉体在GHz频段的介电性能。通过改变Al含量和反应气氛，SiC的多型体由β型（3C）转变为α型（12 H和21 R）。β-SiC粉体的相对介电常数（ε′r=30 <$50）和损耗角正切（tgδ= 10.7）均比α-SiC粉体高得多。虽然Al和N的掺杂使SiC的电阻率降低到102Ω cm量级，但影响其介电性能的关键因素是离子跳跃和偶极弛豫，即晶格缺陷对（VSi-VC，SiC-Csi）的重新取向。SiC的导电性对材料的介电性能影响不大。
In this paper, the dielectric properties of nano-sized SiC powders have been investigated in the GHz frequency range. The polytypes of SiC have been changed from β type (3C) to α type (12H and 21R) by varying the aluminum contents and the reaction atmospheres. The β-SiC powder has much higher relative permittivity (ε′r=30∼50) and loss tangent (tgδ=∼0.7) than α-SiC powders. Though the doping of Al and N decrease the resistivity of SiC to the order of 102Ω cm, the pivotal factor on the dielectric behaviors is ion jump and dipole relaxation, namely the reorientation of lattice defect pairs (VSi–VC, SiC–Csi). The conductivity of SiC has little effect on the dielectric behaviors.