Abstract

Layered hydrated tungsten trioxide with orthorhombic phase is prepared by a hydrothermal method in an acidic environment. Dielectric studies reveal the presence of space charge and ionic polarizations in the as-prepared samples at different temperatures and frequencies. The scaling behavior shows the gradual shifting of space charge to ionic polarization at 343 K. Impedance along with phase measures a shift from purely resistive to capacitive for the sample with an increase in frequency above 343 K. Modular dispersion spectra suggest that electrical transport and conductivity relaxation occur in the material. Nyquist plots are drawn from impedance and modulus data and the activation energies calculated show a transition from metallic to insulating around 343 K. Comparison of variation of imaginary parts of impedance and modulus with frequency shows the movement of grain boundaries to grain, which supports the transition.

中文翻译：

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结构水对水合三氧化钨介电性能的影响

摘要

在酸性环境中，通过水热法制备了具有正交晶相的层状水合三氧化钨。介电研究揭示了在不同温度和频率下制备的样品中存在空间电荷和离子极化。缩放行为表明在343 K处空间电荷逐渐迁移为离子极化。阻抗和相位一起测量的是样品的纯电阻性转变为电容性，并且频率在343 K以上增加。松弛发生在材料中。奈奎斯特图是从阻抗和模量数据中得出的，计算出的活化能表明在343 K附近从金属过渡到绝缘。