Effect of Mn²⁺ substitution on structural, electrical transport and dielectric properties of Mg-Zn ferrites

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• 作者：U.R. Ghodake^a ; Rahul.C. Kambale^b ; S.S. Suryavanshi^c ; ^{sssuryavanshi@rediffmail.com" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Mn-Mg-Zn ferrites ; Oxalate precursors ; X-ray diffraction ; Electrical transport ; Dielectric properties
• 刊名：Ceramics International
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：43
• 期：1
• 页码：1129-1134
• 全文大小：960 K

文摘

Here we have investigated the effect of Mn²⁺ substitution on the structural, electrical transport and dielectric properties of Mg-Zn ferrite having chemical formula Mn_xMg_0.5−xZn_0.5Fe₂O₄ (0.00≤x≤0.30) synthesized by an oxalate precursor chemical method. X-ray diffraction study reveals the formation of single cubic structure with spinel lattice symmetry without secondary phases having the crystallite size in the range from ~ 25.35−30.36 nm. The Mn²⁺ substitution leads to the expansion of spinel lattice unit cell of Mg-Zn ferrite system as evidenced from the increase of lattice constant (a) with respect to Mn²⁺ content. Decrease in the d.c. electrical resistivity as a function of temperature confirms the semiconducting nature of the Mn²⁺ substituted Mg-Zn ferrite; which is attributed to the Verwey hopping mechanism between Fe²⁺⇔ Fe³⁺ ions and Mn²⁺⇔ Mn³⁺. The frequency (100 Hz−1 MHz) dependence dielectric properties viz. dielectric constant and dielectric loss measurement shows the usual dielectric dispersion in accordance with the Maxwell-Wagner type interfacial polarization. The a.c. resistivity measurement (100 Hz−1 MHz) suggests the small polaron hopping type conduction is present in the Mn²⁺ substituted Mg-Zn ferrite system.