Zn取代Cu对CCTO陶瓷高、低频介电性能的影响

Low and Microwave Frequency Dielectric Properties Studies on the CaCu_((3-x))Zn_xTi_4O_(12) Ceramics

采用传统固相法制备了CaCu_((3-x))Zn_xTi_4O_(12)(CCTO,x=0,0.04,0.08,0.12)陶瓷。用X线衍射仪和扫描电子显微镜研究了Zn^(2+)掺杂含量的变化对CaCu_((3-x))Zn_xTi_4O_(12)陶瓷的相结构、微观形貌的影响规律,并研究了CaCu_((3-x))Zn_xTi_4O_(12)陶瓷的低、高频介电性能。结果表明,少量Zn^(2+)的加入影响CaCu_((3-x))Zn_xTi_4O_(12)陶瓷的相结构和微观形貌。在低频范围内,CaCu_((3-x))Zn_xTi_4O_(12)陶瓷均具有巨介电常数(>104),且CaCu_(2.92)Zn_(0.08)Ti_4O_(12)陶瓷的介电常数温度依赖性小,介电损耗最小,这加速了CCTO陶瓷在陶瓷电容器方向应用的潜力。在微波频段(5.85~8.2GHz)范围内,CaCu_((3-x))Zn_xTi_4O_(12)陶瓷均具有介电弛豫现象,CaCu_((3-x))Zn_xTi_4O_(12)陶瓷的介电常数实部随掺杂量的增加而减小,介电常数虚部和损耗对应的频率变化趋势与实部一致。

The CaCu（3-x）ZnxTi4O12（x=0, 0.04, 0.08, 0.12） （CCTO） ceramics have been prepared by the solid state reaction. The effects of the change of Zn^2＋ doping contents on the phase structure and the morphology of CCTO have been investigated by the X-ray diffraction and the scanning electron microscopy, and the low/microwave frequency dielectric properties of CCTO ceramics have also been studied. The results indicate that the addition of small amount of Zn^2＋ doping can influence the phase structure and morphology of CCTO. All the ceramics show the giant dielectric constant （〈10^4）, and the CaCu2. 92 Zn0.08 Ti4 O12 ceramics show the higher dielectric constant, stable temperature dependence of dielectric constant and the lower dielectric loss at the lower frequency. This study is beneficial to design CCTO-based materials and promote their application such as in capacitors. Meanwhile, the dielectric relaxation character exist in the CaCu（3-x）ZnxTi4O12 ceramics at the microwave frequency of （5.85 - 8. 2 GHz） band.