Tb2Fe17和Tb2（Fe,Si）17磁性单晶的生长和相图

利用磁悬浮冷坩埚提拉法技术生长了Tb2Fe17和Tb2(Fe,Si)17的单晶，并用差热分析等方法研究了材料的相图。研究结果表明：Tb2Fe17的相关系并非以往报道的包晶反应。而是同成分熔化。本文还给出了Tb2Fe17化合物附近的新相图。采用优化后的生长条件，获得了缺陷较少的Tb2Fe17和Tb2(Fe,Si)17高质量单晶，分析了Si替代对于化合物结构的影响，测量了Tb2Fe17单晶样品的基本磁性。从材料的一级磁化过程的测量可以看出，在理想配比条件下最容易获得缺陷密度低的单晶样品，这种磁性测量方法为了解单晶的完整性提供了一个有效的间接观察方法。

Growth and Phase Diagram of Tb2Fe17 and Tb2(Fe,Si)17 Single Crystals

Single crystals of rare-earth intermetallic compound of Tb2Fe17 and Tb2(Fe,Si)17 have been grown by CZ method with cold crucible.The phase diagram around Tb2Fe17 has been investigated by various examination methods.It has been found that the phase relation on Tb2Fe17 is not the peritectic,as reported in previous works.A new phase diagram on this compound has been given based on the experimental results,which indicates that the real phase relation on this compound is congruent solidification.This phase relation provides a good intrinsic condition for growing high quality crystal.The X-ray diffraction reveals that the structure of Tb2(Fe,Si)17 become a mixture of Th2Ni17 and Th2Zn17,when the x value is larger than 3.0.The magnetization and the first order magnetization process(FOMP)of the single crystalline samples have been measured,The results indicate that the high quality crystals could be grown from the starting material with stoichiometric composition.Therefore,the magnetic measurement used in the present work will be an effective method for determining the quality of grown single crystals.