The magnetic properties and neutron diffraction studies of Nd3Fe20Cxalloys

The crystal and magnetic structures and magnetic properties of Nd
3
Fe
20
C
x
alloys have been studied. Results of X-ray and neutron diffraction experiments and magnetic measurements showed that the main phase of these alloys has ferromagnetic rhombohedral structure with the symmetry of
R\overline{3}m
space group and the Curie temperature and lattice constants increase with increasing of carbon composition x. The crystal structure of these compounds are based on the rhombohedral structure of Nd
2
Fe
17
and the carbon atoms added preferentially occupy the empty 3a sites, which leads to an increase of Curie temperature and lattice constants. It was indicated by the neutron diffraction spectrum that these compounds have easy-plane anisotropy, which was also comfirmed by the measurements of magnetization curves.