The ac electrical response of hexagonal HoMnO₃ was investigated in the temperature range $340\le T\le 700K$. The combination of impedance and electrical modulus spectra reveal a single dielectric relaxation. However, the ac conductivity in the range $340\le T\le 600K$ revealed two electro-active regions with dissimilar activation energies associated with grain and grain boundary regimes. We suggest that grains have the largest capacitance, whereas grain boundary dominates the overall resistance of the sample. The most interesting was the first-hand observation of a positive temperature coefficient of resistance (PTCR) effect in HoMnO₃, and the sample behaves as an extrinsic semiconductor material. Both bulk effects and grain boundary were observed to contribute together to the PTCR phenomena. A correlation between the ac conductivity and dielectric data was built up. Results show that oxygen non-stoichiometry and associated electron holes are liable for the complex dielectric behavior. The scaling behavior of ac conductivity was studied using different formalisms.

在温度范围内研究了六角形HoMnO ₃的交流电响应$340\le Ť\le 700ķ$。阻抗谱和电模量谱的组合揭示了单个介电弛豫。但是，交流电导率在$340\le Ť\le 600ķ$揭示了两个具有与晶格和晶界制度相关的不同活化能的电活性区域。我们建议晶粒具有最大的电容，而晶界占样品总电阻的主导。最有趣的是在HoMnO _3中对电阻的正温度系数（PTCR）效应的第一手观察，并且该样品表现为非本征半导体材料。观察到体效应和晶界共同导致PTCR现象。建立了交流电导率和介电数据之间的相关性。结果表明，氧的非化学计量和相关的电子空穴对复杂的介电行为负责。的缩放行为使用不同的形式主义研究了交流电导率。