Applied Physics Letters
Nanocomposite ribbons consisting of hard-magnetic R2Fe14B (R = rare-earth) and soft-magnetic Fe3B phases were produced by melt spinning and subsequent heat treatment. Alloys of composition Nd4-xSmxFe77.5B18.5, with x = 0.0, 0.1, 0.2, 0.3, 0.4, and 0.5 all showing strong remanence enhancement, were selected to investigate the effect of the magnetocrystalline anisotropy of the R2Fe14B-type phase on the exchange coupling with the soft-magnetic phase in the nanocomposite magnets. An enhancement of exchange coupling due to anisotropy reduction was found, as expected on the basis of the model of Kneller and Hawig. A maximum of the energy product (BH)(max) was achieved for x = 0.2 after annealing at 700 degrees C. The thermomagnetic behavior also changes upon substitution of Sm for Nd. (C) 1999 American Institute of Physics. [S0003-6951(99)01841-0].
关键词:
remanence
李俊
,
刘新才
,
李明
,
潘晶
功能材料
在850～880℃真空热变形4min、变形量70%制备了Nd14Fe80B6各向异性磁体,实验结果表明随着热变形温度的提高,磁体的各向异性先上升后降低,870℃热变形时磁体的（006）晶面峰为X衍射图谱的主峰、（004）相对极密度最大值达到130.01、I（006）/I（105）为1.88,获得（006）磁织构,磁体的饱和磁化强度达到1.453T。如热变形过程消除平均宽度为25μm的带状组织,减少与热变形压力垂直的片状晶之间夹角为19°左右的局部片状晶,则磁体的各向异性可望进一步提高。Nd2Fe14B相在热变形过程中从等轴晶变形为片状晶,且磁体宏观变形量≥65%时,才能形成（006）磁织构,局部富稀土相只起到有利晶粒滑移、有利片状晶形成的作用。细化热变形磁体的片状晶厚度可使磁体具有高矫顽力、高剩磁与饱和磁化强度之比值。850℃热变形Nd14Fe80B6磁体的片状晶平均厚度为76nm,磁体的矫顽力为450.6kA/m,Mr/Ms为0.92。
关键词:
热变形
,
变形温度
,
剩磁
,
织构
,
显微组织
伍静
,
张敏刚
,
杨丽丽
,
闫晓燕
功能材料与器件学报
doi:10.3969/j.issn.1007-4252.2010.01.013
利用微磁学理论模拟计算了Nd_2Fe_(14) B/α-Fe交换耦合双层膜的磁滞回线,并对双层膜体系的剩磁、矫顽力、最大磁能积与软磁层厚度的关系进行了研究.结果显示,软磁层厚度小于临近尺寸时,磁滞回线为矩形,双层膜完全耦合;软磁层厚度与磁性能的关系表明,随着软磁层厚度的增加,剩磁和最大磁能积先增大后减小,而矫顽力单调下降.
关键词:
微磁学
,
交换耦合
,
剩磁
,
矫顽力
,
磁能积
