Size-manipulation, compaction and electrical properties of barium manganite nanorods synthesized via the CHM method

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• 作者：Khizar Hayat ; M.A. Rafiq ; Atta ur Rahman ; Abid Ali Khan ; M.M. Hasan
• 关键词：BaMnO3 nanorods ; Electrical properties ; Dielectric properties ; DC conduction mechanism
• 刊名：Progress in Natural Science
• 出版年：2013
• 出版时间：August, 2013
• 年：2013
• 卷：23
• 期：4
• 页码：388-394
• 全文大小：2045 K

文摘

A composite-hydroxide mediated method was employed to synthesize barium manganite nanorods. Diameter, surface smoothness and uniformity of these nanorods were optimized by varying reaction temperature and reaction time. The rods with an average diameter of 200 nm and length of 1-1.5 ¦Ìm were obtained at optimum conditions of 200 ¡ãC/48 h. The dielectric study of these rods reveals that they have higher value of dielectric constant at lower frequencies which was attributed to the interfacial and rotational type polarizations. Similarly, the increase in dielectric constant with temperature was attributed to the thermal activation of such polarizations. Furthermore, the analysis of ln(J) vs. E^1/2 characteristics in the temperature range of 300-400 K shows that possible operative conduction mechanism was of Poole-Frenkel type. The value of ¦Â_exp was found to be 4.85 times greater than the expected theoretical value of field lowering coefficient with an internal field enhancement factor of ¦Á²=23.5. This high value of ¦Â_exp may be due to some localized electric fields existing inside the sample.