THE FORMATION AND MAGNETIC-PROPERTIES OF SM2FE15AL2CX (X=0-2.0) COMPOUNDS PREPARED BY ARC MELTING

The structural and magnetic properties of compounds in the series Sm2Fe15Al2Cx, have been investigated by means of x-ray diffraction (XRD) and magnetization measurements. Samples with x = 0, 0.5, 1.0, 1.5, and 2.0 were prepared by the arc-melting method. XRD patterns indicate that these carbides are single phase with a rhombohedral Th2Zn17-type structure, except for Sm2Fe15Al2, which contains a few per cent of BCC alpha-Fe. The saturation magnetization for all samples is about 110 emu g-1 and has a small dependence on C concentration. The Curie temperature T(C) enhancement is about 190 K for x = 1.5 compared with that of Sm2Fe17. All compounds exhibit an easy c-axis anisotropy at room temperature and the anisotropy field increases to about 110 kOe when x less-than-or-equal-to 1.5. The substitution of Al, like Ga and Si, is found to not only help the formation of high-C-concentration rare-earth-Fe compounds with 2:17-type structure, but also increase the anisotropy field.