M型永磁铁氧体的现状与进展

评述了M型永磁铁氧体的现状与进展，讨论了M型永磁铁氧体在工业生产中的关键技术问题，如预烧工艺、微粉加工、料浆在磁场成型时的取向，详细地调研了高性能锶铁氧体的化学成分、显微结构、宏观的和亚微观的磁性能，^57FeMossbauer谱显示非化学计量的M型永磁铁氧体性能与4f1与4f2晶位谱线强度相关，La2O3掺杂对稳定磁铅石结构和提高产体性能有益。La^3 和Zn^2 联合取代对M型六铁氧体晶粒取向度、质量密度、亚微米尺寸结构和饱和磁化强度有明显的作用，正像人们期望的那样，M型锶铁氧体的Br和（BH）max取得了显著的进展。

Present States and Recent Advances in M-Type Ferrites

Present states and recent advances in M-type permanent ferrites are reviewed in this paper． The key te chnology for the manufacturing of M -type ferrites with high performan ces such as pre-sintering， micro-c rushing and magnetic orientating in pres sing with magnetic field is discussed． T his paper has described the promisi ng ideas and processes in order to improve the properties of sintere d M-type magnets in industry in th e future． Commercial high-energy p roduct strontium hexaferrites have in detail been characterized in t ems of their chemical compositions ， microstructures， and bulk and su bmicroscopic magnetic properties． 57Fe Mssbauer spectro scopy shows that the magnetic prope rties of nonstoichiometric M-Type ferrites correlates with the relat ive intensity of the pattern assig ned to the 4f1 and 4f2 sites． Th e La2O3 additiion to SrO*6Fe2O 3 is very useful in stabilizing th e magnetoplumbite structure and th ese Sr-La-system ferrites have exc ellent properties as a permanent m agnet． Lanthanum and zinc substitu tion in M-type hexaferrite can ach ieve high orientation degree，high mass density， submicronsized grain s and high saturation magnetizatio n． The Br and （BH）max has greatly advanced in M-type Sr-ferr ites as hoped．