Skip to Main Content
The structural and magnetic properties of Tm2CrFe16-xSix (x=0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0) compounds are investigated by means of X-ray diffraction and magnetization measurements. The results show that the Tm2CrFe16-xSix compounds are in a single phase with the hexagonal Th2Ni17-type structure. The lattice parameters a and c and the unit-cell volume v decrease monotonously with x increasing. The Curie temperature TC increases initially (x <; 1.5) with x increasing, followed by a decrease at higher concentrations (x >; 1.5) . There is a maximum of the Curie temperature, which is about 450 K, at x=1.5. Spin reorientations are observed in the temperature dependences of the magnetization of Tm2CrFe16-xSix compounds. The spin reorientation temperature (Tsr) increases from 144 K at x=0 to 259 K at x=3.0 with x increasing. This means that the Si atoms substituting for Fe atoms can increase obviously the easy-axis magnetocrystalline anisotropy. The analysis shows that the effect of Cr substitution and the effect of Si substitution on the Curie temperature and the magnetocrystalline anisotropy of R2Fe17 compound can be superposed.