Anomalous thermal expansion of R(Fe, Mo)12 compounds
R(Fe，Mo)12型稀土永磁材料热膨胀反常现象研究

The R(Fe, Mo)- 12 (R Nd, Y, Dy) samples have been prepared and measured by x-ray diffraction at different temperatures. The crystal lattice constants and degree of the thermal expansion along the different axes are calculated. As a result, we consider that the abnormally thermal expansion of R(Fe, Mo)- 12 compounds is mainly determined by the Fe-Fe interaction. According to structural parameters of Nd(Fe, Mo)- 12 , the anomaly is caused not only by the short Fe-Fe interaction as the previous explanation on other R-Fe intermetallic compounds but also by the other strongly positive Fe-Fe interactions. The mechanism of the substitution by Mo affecting the thermal expansion anomalies is also discussed.