Sm2Fe17化合物的吸氮反应研究

通过X-射线衍射、差热-热重（DTA-TG）联用仪以及磁测量等手段,研究了Sm2Fe17化合物吸氮后的相结构及居里温度的变化行为.X-射线衍射表明,吸氮后Sm2Fe17化合物的衍射峰向小角度方向偏移,并且出现了α-Fe的衍射峰,这说明吸氮后化合物的晶胞有所膨胀,并且化合物有一定的分解,产生了α-Fe.差热-热重分析表明,在温度为700 K左右时Sm2Fe17化合物的吸氮反应最剧烈,吸氮以后化合物的居里温度TC有显著的提高;而且随着温度的继续升高,在吸氮反应的同时,Sm2Fe17Nx化合物不稳定,部分分解为SmN化合物和α-Fe.实验结果分析表明,该化合物在1 473 K以下时,只存在Th2Zn17型结构,不存在Th2Ni17型结构.

On the reaction of nitrogen absorption of the Sm2Fe17 compound

The changes in phase structure and Curie temperature of the Sm2Fe17 compound after nitrogen absorption were studied by using X-ray diffraction,differential thermal/thermo-gravimetric analyzer and magnetic measurement.The results of X-ray diffraction showed that the diffraction peaks of the Sm2Fe17 compound shifted toward lower angle after nitrogen absorption,and the characteristic peaks of α-Fe were observed.This showed that the unit cell of Sm2Fe17 expanded,the compound was decomposed to a certain extent and the characteristic peaks of α-Fe appeared.The results of DTA-TG showed that the reaction of nitrogen absorption of the Sm2Fe17 was most violent at the temperature of 700 K,and its Curie temperature TC increased remarkable after nitrogen absorption.In the process of nitrogen absorption,with the continuously increase of the temperature the Sm2Fe17Nx was unstable and part of it was decomposed into SmN compound and α-Fe.The results of the experiment showed that the Sm2Fe17 and Sm2Fe17Nx exhibited Th2Zn17-type structure only but didn＇t exhibited Th2Ni17-type structure below the temperature of 1 473 K.