无机材料学报

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二价铁过量M型钡铁氧体的放电等离子体烧结合成

魏 平, 赵文俞, 吴晓艳, 张清杰   

  1. 武汉理工大学 材料复合新技术国家重点实验室, 武汉 430070
  • 收稿日期:2008-08-28 修回日期:2008-10-21 出版日期:2009-05-20 网络出版日期:2009-05-20

M-type Barium Hexaferrite with Excessive Divalent Iron Synthesized by Spark Plasma Sintering Method

WEI Ping, ZHAO Wen-Yu, WU Xiao-Yan, ZHANG Qing-Jie   

  1. State Key Laboratory of Advanced Technology for Materials Synthesis and Processing,Wuhan University of Technology, Wuhan 430070, China
  • Received:2008-08-28 Revised:2008-10-21 Published:2009-05-20 Online:2009-05-20

摘要: 在氩气保护下用化学共沉淀工艺制备了名义组成为BaFe3+11.8Fe2+0.3O19的Fe2+过量M型钡铁氧体(BaM)前驱体,采用XRD、SEM和Archimedes法研究了前驱体在放电等离子体烧结(SPS)条件下的物相组成、显微结构和致密度. 结果表明,合成高致密度的单相Fe2+过量BaM材料的优化SPS工艺为850℃、保温30min和压力10MPa,其结晶机制为低温下前驱体分解形成α-Fe2O3和Fe3O4或γ-Fe2O3,高温下Fe2+过量BaM结晶,整个结晶过程中没有BaFe2O4中间相形成. 单相Fe2+过量BaM材料的饱和磁化强度为58.2A·m2·kg-1,矫顽力为255kA·m-1, 说明Fe2+占据自旋向上的2a磁晶位.

关键词: Fe2+过量M型钡铁氧体, 放电等离子体烧结, 结晶机制, 磁性能

Abstract: The precursor of M-type barium hexaferrite (BaM) with excessive divalent iron BaFe3+11.8Fe2+0.3O19 was prepared by chemical coprecipitation process in Ar atmosphere. The phase compositions, microstructures, and densities of sintered products synthesized by spark plasma sintering (SPS) method were investigated with XRD, SEM and Archimedes methods. The optimizing SPS condition for synthesizing singlephase and highcompactness BaM materials with excessive divalent iron is holding for 30min at 850℃ and 10MPa. The crystalline reaction process is composed of the decomposition of the precursor into α-Fe2O3 and Fe3O4 or γ-Fe2O3 at low temperature and the crystallization of BaM with excessive Fe2+ at hightemperature, without intermediate phase BaFe2O4 forming in the whole process. Saturation magnetization and coercivity of singlephase BaM materials with excessive divalent iron are of 58.2A·m2·kg-1 and 255kA·m-1, respectively, which imply that the excessive divalent irons spin upward at 2a site in FeO6 octahedron.

Key words: M-type barium hexaferrite with excessive divalent iron, spark plasma sintering, crystalline mechanism, magnetic property

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