Phase diagram of the Fe-rich portion of R-Fe-Al pseudoternary system(R=Dy_(0.65)Tb_(0.25)Pr_(0.1))

The 1000℃ isothermal section of the Fe-rich portion of R-Fe-Al(R=Dy0.65Tb0.25Pr0.1) pseudoternary system has been investigated using optical microscopy,X-ray diffraction,EPMA and DTA techniques.The 1000℃ isothermal section consists of 9 single-phase regions,14 two-phase regions and 6 three-phase regions.In the R-Fe pseudobinary system,except the R2Fe17 compound,the homogeneity regions of other compounds are shifted towards the stoichiometric rare earth-rich side.With Fe partially substituted by Al,the homogeneity region of R(Fe1-xAlx)2 is shifted back to the stoichiometric composition when x=0.15 and remains little changed with 0.15≤x≤0.30.The homogeneity regions of R(Fe1-xAlx)3 and R6(Fe1-xAlx)23 are slightly shifted to the stoichiometric rare earth-rich side with increasing Al content.A vertical section along R=33.33 atomic percentage is also investigated.It consists of 2 single-phase regions,4 two-phase regions and 2 three-phase regions.     

Dy0.6Tb0.3Pr0.1(Fe0.95Mn0.05)x取向晶体的结构与磁致伸缩

采用Ｃｚｏｃｈｒａｌｓｋｉ方法生长了Ｄｙ０．６Ｔｂ０．３Ｐｒ０．１（Ｆｅ０．９５Ｍｎ０．０５）ｘ（１．８５≤ｘ≤１．９５）取向合金。所有合金主相为立方Ｌａｖｅｓ相结构,择优取向不完整择优取向的方向与Ｘ的大小有关。研究了沿着这些样品的生长方向的磁致伸缩性能以及磁致伸缩性能与压力之间的关系。     

机械合金化Nd-11Fe-Ti合金和机械研磨NdFe11Ti化合物退火时的相转变

采用X射线衍射、初始交流磁性率和差热分析研究了机械合金化Nd-11Fe-Ti(原子比)合金粉和机械研磨NdFe11Ti化合物粉在退火过程中的相转变.球磨7 h后二者均由非晶相和Ti在α-Fe中过饱和固溶体组成.机械合金化粉末样品中的非晶相的晶化温度为620℃,晶化亚稳相为TbCu7结构的Nd(Fe,Ti)7,900℃以上退火时,亚稳相转变成ThMn12结构Nd(Fe,Ti)12相;机械研磨的NdFe11Ti化合物粉中非晶相在638℃晶化形成的Nd(Fe,Ti)7在1000℃以上退火向Nd(Fe,Ti)12相转变.这些差别归因于两种样品中Ti原子在非晶相与α-Fe相中分配的不同.     

机械合金化方法制备的Nd(Fe,V)12Nδ磁体的结构与磁性

用机械合金化方法研究了ＮｄＦｅ１２－ｘＶｘＮδ各向同性粉末的结构和永磁性能,发现在７００－９００℃退火机械合金化粉末时,除了钒含量ｘ＝１的样品在７５０℃以下退火时,晶化不完全,有大量的α－Ｆｅ（Ｖ）相析出外,其科的样品在７００－９００℃退火温度范围内都形成了Ｎｄ（Ｆｅ,Ｖ）１２相。氮化后,体积膨胀约为５％居里温度提高１４０－１６０℃．ＮｄＦｅ１２－ｘＶＮδ氮化物的居里温度为４６９－４８５℃,增加钒