二价铁过量M型钡铁氧体的放电等离子体烧结合成  

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

作　　者：魏平[1] 赵文俞[1] 吴晓艳[1] 张清杰[1] 

机构地区：[1]武汉理工大学材料复合新技术国家重点实验室,武汉430070

出　　处：《无机材料学报》2009年第3期586-590,共5页Journal of Inorganic Materials

基　　金：国家自然科学基金(50572083)

摘　　要：在氩气保护下用化学共沉淀工艺制备了名义组成为BaFe131+.8Fe02.+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.The precursor of M-type barium hexaferrite （BaM） with excessive divalent iron BaFe131＋.8Fe02.＋3O19 was prepared by chemical eopreeipitation 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 BaN 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 T-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 singlephase 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 2α site in FeO6 octahedron.

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 

分 类 号：O482[理学—固体物理]