Preparation of high quality, single domain BaFe₁₂O₁₉ particles by the citrate sol-gel combustion route with an initial Fe/Ba molar ratio of 4

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• 作者：H. Sö ; zeri^a ; ^{huseyin.sozeri@ume.tubitak.gov.tr} ; Z. Durmu艧^b ; A. Baykal^b ; E. Uysal^a
• 关键词：Magnetic materials ; Sol&ndash ; gel growth ; Magnetic properties
• 刊名：Materials Science and Engineering ; B
• 出版年：2012
• 期刊代码：76_09215107
• 类别：ch
• 出版时间：25 July, 2012
• 卷：177
• 期：12
• 页码：949-955
• 文件大小：1276 K

摘要

BaFe₁₂O₁₉ particles have been synthesized by citrate sol-gel combustion route in a wide temperature range between 800 and 1200 掳C with initial Fe/Ba molar ratios between 12 and 2. Structural, morphological and magnetic properties of the powders have been investigated by XRD, FT-IR, SEM and magnetization measurements. It was observed that both coercivity and specific saturation magnetization increase with annealing at temperatures up to 1100 掳C, where a transition from single to multi domain structure occurs. To prevent formation of the hematite phase (伪-Fe₂O₃), samples with different Fe/Ba molar ratios between 12 and 2 have been prepared and an intermediate phase, BaFe₂O₄, which may occur in Ba-rich samples has been removed by etching the powders in diluted hydrochloric acid. In this way, it was shown that single domain barium hexaferrite particles having high saturation magnetization, close to the theoretical value, and high coercivity can be synthesized with the initial Fe/Ba molar ratio of 4 in the sol-gel method. The chemical composition of this sample was determined as BaFe_11.80O_19.45 by the EDS analysis and Ba_1.05Fe_11.54O_18.4 using an ICP-MS device. Both are very close to the theoretical formula.