Investigations on dielectric and impedance properties of M-type hexaferrite

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• 作者：K. Alamelu Mangai ; K. Tamizh Selvi ; M. Priya…
• 刊名：Journal of Materials Science: Materials in Electronics
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：28
• 期：3
• 页码：2910-2922
• 全文大小：
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Optical and Electronic Materials; Characterization and Evaluation of Materials;
• 出版者：Springer US
• ISSN：1573-482X
• 卷排序：28

文摘

The M-type strontium hexaferrite SrFe₁₂O₁₉ nano particles with nominal composition were prepared by self-propagating high temperature synthesis route. The ac conductivity and dielectric properties of SrFe₁₂O₁₉ samples were studied by using complex impedance technique. The dielectric properties like dielectric constant (\( \upvarepsilon^{\prime } \)), dielectric loss (tan δ) and ac conductivity (σ_ac) were measured at different calcination temperatures in the frequency ranges from 50 Hz to 5 MHz. The frequency dependence of ac conductivity is analysed by the power law σ(ω)_ac = Bωn which is typical for charge transport by tunnelling processes. The temperature dependence of frequency exponent n was investigated to understand the conduction mechanism at different calcination temperatures. The conduction mechanisms are mainly based on polaron hopping conduction. The results of the cole–cole diagram of \( {\text{Z}}^{\prime } \) and \( - {\text{Z}}^{{\prime \prime }} \) at different temperatures ensure the presence of grain and grain boundaries having different conductivities in the investigated nano particle samples. The dielectric and impedance properties of the prepared strontium hexaferrite samples were discussed in view of applications for microwave devices, permanent magnets and high frequency magnetic recording media.