MnZn power ferrite with high B_s and low core loss

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• 作者：Dong Liu ; Xiaping Chen ; Yao Ying ; Ling Zhang ; Wangchang Li ; Liqiang Jiang ; Shenglei Che ; ^{cheshenglei@zjut.edu.cn" class="auth_mail" title="E-mail the corresponding author}
• 关键词：A. Sintering ; B. Grain size ; C. Electromagnetic properties ; D. Manganese-zinc ferrite ; E. Soft magnets
• 刊名：Ceramics International
• 出版年：2016
• 出版时间：15 May 2016
• 年：2016
• 卷：42
• 期：7
• 页码：9152-9156
• 全文大小：1347 K

文摘

Although there is a tradeoff between high B_s and low core loss for MnZn power ferrite, in the current work, high B_s and a low core loss (P_cv) were achieved simultaneously by increasing the content of Fe₂O₃ and by adjusting the partial pressure of oxygen (P_O2) during sintering process, respectively. Additionally, the influence of P_O2 on the P_cv was also investigated. The MnZn ferrite cores were prepared by conventional ceramic process. With increase in P_O2 from 0.35% to 1.90%, the bottom temperature of P_cv(T) curve shifted to a higher temperature, and simultaneously the minimum P_cv at the bottom temperature decreased continuously. P_cv in a low frequency range was divided into the hysteresis loss (P_hv) and eddy current loss (P_ev). Both P_hv and P_ev decreased with increasing P_O2. At high P_O2 cation vacancy was generated, which facilitated the transport of dopant, such as Ca and Si to the grain boundary region. This induced high resistance at the grain boundary which in turn reduced the P_ev. Meanwhile, the transport of dopants from intragranular to grain boundary also reduces the defects in grains, which helped to decrease the P_hv, coercivity and remanence.