Origin(s) of the apparent colossal permittivity in (In1/2Nb1/2)xTi1−xO2: clarification on the strongly induced Maxwell–Wagner polarization relaxation by DC bias
Origin(s) of the apparent colossal permittivity in (In1/2Nb1/2)xTi1−xO2: clarification on the strongly induced Maxwell–Wagner polarization relaxation by DC bias
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DOI：
10.1039/c6ra26728a
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发表时间：
2017
期刊：
影响因子：
3.9
通讯作者：
Wattana Tuichai;Supamas Danwittayakul;N. Chanlek;P. Srepusharawoot;P. Thongbai;S. Maensiri
中科院分区：
文献类型：
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作者：
Wattana Tuichai;Supamas Danwittayakul;N. Chanlek;P. Srepusharawoot;P. Thongbai;S. Maensiri
研究了直流偏压对共掺杂（In1/2Nb1/2）xTi1−xO2 (IN-T) （x = 0.05和0.1）和单掺杂Ti0.975Nb0.025O2陶瓷介电性能和电学性能的影响。在40 V和20 V的直流偏压下，x = 0.05和0.1的IN-T陶瓷的低频介电常数（e′）和损耗正切值大大增强，而相对高频的e′保持不变。立即施加直流偏压，诱导的低频麦克斯韦-瓦格纳极化完全消失。在过载限制测量后，这种极化永久出现，没有直流偏置，而初级极化保持不变。结合Z′′和M′′谱图，发现强诱导极化是由样品电极接触和电阻性外表面的共同作用引起的。in - t陶瓷中巨大介电常数的优异性能主要归功于其外表层的电阻性和绝缘晶界的形成。这些结果不仅对in - t陶瓷体系中巨大介电响应的起源提供了重要的见解，而且对于确定实际应用中tio2基材料的掺杂条件也很重要。
The effects of DC bias on the dielectric and electrical properties of co-doped (In1/2Nb1/2)xTi1−xO2 (IN-T), where x = 0.05 and 0.1, and single-doped Ti0.975Nb0.025O2 ceramics are investigated. The low-frequency dielectric permittivity (e′) and loss tangent of IN-T ceramics with x = 0.05 and 0.1 are greatly enhanced by applying a DC bias at 40 and 20 V, respectively, whereas the relatively high-frequency e′ remains unchanged. The induced low-frequency Maxwell–Wagner polarization completely vanishes by immediately applying no DC bias. After overload limited measurement, this polarization permanently emerges without DC bias, whereas the primary polarization remains unchanged. Using combined Z′′ and M′′ spectroscopic plots, it is found that the strongly induced-polarizations are contributed from the combination effects of the sample–electrode contact and resistive outer surface. Very high performance of the colossal permittivity in IN-T ceramics is attributed to the formation of a resistive outer-surface layer and insulating grain boundaries. These results not only provide important insights into the origins of the colossal dielectric response in the IN-T ceramic system, but are also important for deciding the doping conditions of TiO2-based materials for practical applications.