Electrical Conductivity Mechanism in Unconventional Lead Vanadate Glasses

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• 作者：F. Abdel-Wahab ; A. Merazga ; A. A. Montaser
• 关键词：Lead vanadate glasses ; Press ; quenching technique ; Multi ; phonon process ; Percolation path approximation ; Dielectric relaxation time
• 刊名：Journal of Low Temperature Physics
• 出版年：2017
• 出版时间：March 2017
• 年：2017
• 卷：186
• 期：5-6
• 页码：372-384
• 全文大小：
• 刊物类别：Physics and Astronomy
• 刊物主题：Condensed Matter Physics; Characterization and Evaluation of Materials; Magnetism, Magnetic Materials;
• 出版者：Springer US
• ISSN：1573-7357
• 卷排序：186

文摘

Lead vanadate glasses of the system \((\hbox {V}_{2}\hbox {O}_{5})_{1-x}(\hbox {PbO})_{x}\) with \(x = 0.4\), 0.45, 0.5, 0.55, 0.6 have been prepared by the press-quenching technique. The dc (\(\sigma (0)\)) and ac \((\sigma (\omega ))\) electrical conductivities were measured in the temperature range from 150 to 420 K and the frequency range from \(10^{2}\) to \(10^{6}\) Hz. The electrical properties are shown to be sensitive to composition. The experimental results have been analyzed within the framework of different models. The dc conductivity is found to be proportional to \(T^{p}\) with the exponent p ranging from 8.2 to 9.8, suggesting that the transport is determined by a multi-phonon process of weak electron-lattice coupling. The ac conductivity is explained by the percolation path approximation (PPA). In this model, \(\sigma \)\((\omega )\) is closely related to the \(\sigma (0)\) and fitting the experimental data produces a dielectric relaxation time \(\tau \) in good agreement with the expected value in both magnitude and temperature dependence.