CaCu_3Ti_4O_(12)陶瓷的高温介电弛豫研究
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摘要
研究过渡金属氧化物在交变电场中的极化和弛豫行为有助于对此类化合物的输运机制的理解和介电、铁电等性能的优化.本文利用宽温宽频介电分析仪研究了CaCu_3Ti_4O_(12)(CCTO)陶瓷在室温以上的介电常数、弛豫和阻抗等性质.通过对阻抗谱的拟合分析表明,与室温以下介电弛豫机制不同,高温弛豫激活能与晶界电导激活能完全一致,说明高温下介电弛豫源于多晶陶瓷的晶界效应.
The study of polarization and relaxation behavior for transition-metal oxides in alternating electric field is meaningful for the interpretation of their transport mechanism,dielectric and ferroelectric properties.The dielectric permittivity,relaxation and impedance properties above room temperature for CaCu_3Ti_4O_(12)(CCTO)ceramic were studied by dielectric analyzer in a wide range of temperature and frequency.The fitting results of impedance indicate that the activation energy for high temperature is equal to that of electric conduction of grain boundary,which is different from the dielectric relaxation mechanism below room temperature.Our results suggest that the dielectric relaxation at high temperature is originated from the grain boundary effects of polycrystalline ceramic.
The study of polarization and relaxation behavior for transition-metal oxides in alternating electric field is meaningful for the interpretation of their transport mechanism,dielectric and ferroelectric properties.The dielectric permittivity,relaxation and impedance properties above room temperature for CaCu_3Ti_4O_(12)(CCTO)ceramic were studied by dielectric analyzer in a wide range of temperature and frequency.The fitting results of impedance indicate that the activation energy for high temperature is equal to that of electric conduction of grain boundary,which is different from the dielectric relaxation mechanism below room temperature.Our results suggest that the dielectric relaxation at high temperature is originated from the grain boundary effects of polycrystalline ceramic.
引文
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[6] T.-T.Fang,C. P. Liu. Evidence of the internal domains for inducing the anomalously high dielectric constant of Ca Cu3Ti4O12[J]. Chemistry of Materials,2005,17:5167-5171.
[7] T. Fang,L. Mei,H. Ho. Effects of Cu stoichiometry on the microstructures,barrier-layer structures,electrical conduction,dielectric responses,and stability of CaCu3Ti4O12[J].Acta Materialia,2006,54:2867-2875.
[8] R.K.Pandey,W.A.Stapleton,J.Tate et al.Applications of CCTO supercapacitor in energy storage and electronics[J].AIP Advances,2013,3(6):21-26.
[9]李含,刘璐,张强,等.固相法制备Ca Cu3Ti4O12及其结构与介电性能的研究[J].吉林化工学院学报,2016,33(11):104-107.
[10]刘军伟,刘巧丽,赵方辉,等.Ca Cu3Ti4O12陶瓷的制备及低温介电弛豫研究[J].吉林化工学院学报,2016,33(11):97-99.
[11] J.Liu,C. Duan,W. Yin,et al. Large dielectric constant and Maxwell-Wagner relaxation in Bi2/3Cu3Ti4O12[J].Physics Review B,2004,70:144106.
[2] M.H.Cohen,J.B.Neaton,L.He,et al.Extrinsic models for the dielectric response of Ca Cu3Ti4O12[J].Journal of Applied Physics,2003,94:3299-3306.
[3] P. Lunkenheimer,V.Bobnar,A.V.Pronin,et al.Origin of apparent colossal dielectric constants[J]. Physics Review B,2002,66:052105.
[4] D. C. Sinclair,T. B. Adams,F. D. Morrison,et al. CaCu3Ti4O12:One-step internal barrier layer capacitor[J].Applied Physics Letters,2002,80:2153.
[5] T.B.Adams,D.C.Sinclair,A.R.West.Giant barrier layer capacitance effects in Ca Cu3Ti4O12 ceramics[J]. Advanced Materials,2002,14:1321-1323.
[6] T.-T.Fang,C. P. Liu. Evidence of the internal domains for inducing the anomalously high dielectric constant of Ca Cu3Ti4O12[J]. Chemistry of Materials,2005,17:5167-5171.
[7] T. Fang,L. Mei,H. Ho. Effects of Cu stoichiometry on the microstructures,barrier-layer structures,electrical conduction,dielectric responses,and stability of CaCu3Ti4O12[J].Acta Materialia,2006,54:2867-2875.
[8] R.K.Pandey,W.A.Stapleton,J.Tate et al.Applications of CCTO supercapacitor in energy storage and electronics[J].AIP Advances,2013,3(6):21-26.
[9]李含,刘璐,张强,等.固相法制备Ca Cu3Ti4O12及其结构与介电性能的研究[J].吉林化工学院学报,2016,33(11):104-107.
[10]刘军伟,刘巧丽,赵方辉,等.Ca Cu3Ti4O12陶瓷的制备及低温介电弛豫研究[J].吉林化工学院学报,2016,33(11):97-99.
[11] J.Liu,C. Duan,W. Yin,et al. Large dielectric constant and Maxwell-Wagner relaxation in Bi2/3Cu3Ti4O12[J].Physics Review B,2004,70:144106.