Origin of colossal dielectric permittivity of rutile Ti₀.₉In₀.₀₅Nb₀.₀₅O₂: single crystal and polycrystalline.
Origin of colossal dielectric permittivity of rutile Ti₀.₉In₀.₀₅Nb₀.₀₅O₂: single crystal and polycrystalline.
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金红石Ti0.9In0.05Nb0.05O2大介电常数的来源：单晶和多晶
DOI：
10.1038/srep21478
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发表时间：
2016-02-12
影响因子：
4.6
通讯作者：
Tang J
中科院分区：
文献类型：
--
作者：
Song Y;Wang X;Sui Y;Liu Z;Zhang Y;Zhan H;Song B;Liu Z;Lv Z;Tao L;Tang J
本文研究了（In + Nb）共掺杂金红石型TiO2单晶和多晶陶瓷的介电性能。他们都表现出巨大的，高达104，在室温下的介电常数。单晶样品表现出一个介电弛豫过程，具有较大的介电损耗。介电常数的电压依赖性和阻抗谱表明，高介电常数的单晶起源于表面势垒层电容器（SBLC）。不同温度下的交流阻抗谱证实了（In + Nb）共掺杂金红石型TiO2多晶陶瓷具有半导体晶粒和绝缘晶界，计算出晶粒和晶界的激活能分别为0.052 eV和0.35 eV。多晶陶瓷样品的介电行为和阻抗谱表明，内势垒层电容（IBLC）模式，而不是电子钉扎的缺陷偶极子的高陶瓷介电常数作出了主要贡献。
In this paper, we investigated the dielectric properties of (In + Nb) co-doped rutile TiO2 single crystal and polycrystalline ceramics. Both of them showed colossal, up to 104, dielectric permittivity at room temperature. The single crystal sample showed one dielectric relaxation process with a large dielectric loss. The voltage-dependence of dielectric permittivity and the impedance spectrum suggest that the high dielectric permittivity of single crystal originated from the surface barrier layer capacitor (SBLC). The impedance spectroscopy at different temperature confirmed that the (In + Nb) co-doped rutile TiO2 polycrystalline ceramic had semiconductor grains and insulating grain boundaries, and that the activation energies were calculated to be 0.052 eV and 0.35 eV for grain and grain boundary, respectively. The dielectric behavior and impedance spectrum of the polycrystalline ceramic sample indicated that the internal barrier layer capacitor (IBLC) mode made a major contribution to the high ceramic dielectric permittivity, instead of the electron-pinned defect-dipoles.