用中子衍射研究稀土-富铁永磁合金磁结构和D(H)LAP晶体结构

NEUTRON DIFFRACTION STUDIES OF THE MAGNETIC STRUCTURE OF RARE EARTH IRON RICH PERMANENT MAGNETIC ALLOYS AND THE CRYSTALLOGRAPHIC STRUCTURE OF D(H)LAP

用粉末中子衍射测量了Ｈｏ２Ｆｅ９Ｇａ８－ ｘＡｌｘ（ｘ＝ ２、４）和ＰｒＦｅ１０．５Ｍｏ１．５Ｎｘ 的晶体结构和磁结构。衍射数据分别用Ｒｉｅｔｖｅｌｄ 结构精修程序ＲＩＥＴＡＮ和Ｆｕｌｌｐｒｏｆ处理。确定了替代原子Ｇａ、Ａｌ、Ｍｏ 及间隙原子Ｎ 的占位数以及磁性原子Ｈｏ、Ｆｅ、Ｐｒ 的原子磁矩的大小和方向。Ｈｏ２Ｆｅ９Ｇａ６Ａｌ２ 在室温和５０ Ｋ、Ｈｏ２Ｆｅ９Ｇａ４Ａｌ４ 在５０ Ｋ下呈亚铁磁性且为单轴各向异性，ＰｒＦｅ１０．５Ｍｏ１．５吸氮前后磁各向异性由易面变为易轴。

The crystallographic and magnetic structure of Ho 2Fe 9Ga 8- x Al x ( x =2,4) and PrFe 10.5 Mo 1.5 N x compounds are studied by powder neutron diffraction. The atom fractional occupancies of Ga, Al, Mo and N and the atom magnetic moments of Ho, Fe and Pr are obtained by Rietveld analysis program. For Ho 2Fe 9Ga 8- x Al x ( x =2,4), the magnetic moments of the phase with the x =2,4 at 50 K and x =2 at 300 K show uniaxial magnetic anisotropy. PrFe 10.5 Mo 1.5 N x compound exhibits easy axis magnetic anisotropy, but the anisotropy of PrFe 10.5 Mo 1.5 is easy planar. The crystal structure of D(H)LAP is determined by single crystal neutron diffraction. The results indicate that the deuteriums occupy hydrogen positions except those hydrogen atoms bonded to carbon atoms.