Electrical and dielectric studies of substituted holmium based pyrochlore zirconates nanomaterials
Electrical and dielectric studies of substituted holmium based pyrochlore zirconates nanomaterials
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DOI：
10.1016/j.jallcom.2015.08.189
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发表时间：
2015-12
影响因子：
6.2
通讯作者：
Nazia Karamat;I. Ali;A. Aziz;M. Sher;M. Ashiq
中科院分区：
文献类型：
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作者：
Nazia Karamat;I. Ali;A. Aziz;M. Sher;M. Ashiq
The effects of Ge4+cation substitution on the structure, morphology, electrical and dielectric properties of rare earth pyrochlore oxides (Ho2Zr2-xGexO7, 0.00 ≤ x ≤ 1.0) were investigated.采用微乳液法制备烧绿石氧化物。 XRD数据Ge+4取代的Ho2Zr2-xGexO7显示出立方结构。室温直流电阻率随着Ge4+含量的增加而增加。 The value of exponent ‘n’ calculated from the plot of log(σ) versus log(ω) ranges 0.78–0.95 suggested that the conduction phenomena in the studied samples pursue hopping conduction.奈丘斯特图（科尔-科尔图）用于研究材料中的弛豫现象。图中半圆的可视化表示晶界占据较小的体积。介电损耗随频率的变化显示出共振峰。介电损耗在 1.3 GHz 以下稳定。 Such frequency independent characteristic of the high dielectric constants Ho2Zr2-xGexO7ceramics and their low dielectric losses make them more attractive in the applications of multilayer ceramic capacitors and resonators.电阻率随着取代而增加，使得这些材料适用于微波器件。
The effects of Ge4+cation substitution on the structure, morphology, electrical and dielectric properties of rare earth pyrochlore oxides (Ho2Zr2-xGexO7, 0.00 ≤ x ≤ 1.0) were investigated. The pyrochlore oxides were prepared by the microemulsion method. The XRD data Ge+4substituted Ho2Zr2-xGexO7reveal a cubic structure. Room temperature DC electrical resistivity increases on increasing the Ge4+contents. The value of exponent ‘n’ calculated from the plot of log(σ) versus log(ω) ranges 0.78–0.95 suggested that the conduction phenomena in the studied samples pursue hopping conduction. Nyqiust plot (cole–cole plot) was used to study relaxation phenomenon in the material. The visualization of semicircles in plot represent that grain boundary occupies small volume. The dielectric loss with frequency shows resonance peaks. The dielectric losses were stable below 1.3 GHz. Such frequency independent characteristic of the high dielectric constants Ho2Zr2-xGexO7ceramics and their low dielectric losses make them more attractive in the applications of multilayer ceramic capacitors and resonators. The increase in resistivity with substitution makes these materials suitable for microwave devices.