MAGNETIC-PROPERTIES OF SM2FE17-XGAXC2 COMPOUNDS

The Sm2Fe17-xGaxC2 (x = 0, 2, 3, 4, 5 and 6) samples were prepared by are melting. X-ray diffraction shows that these alloys are single-phas e compounds of the rhombohedral Th2Zn17-type structure except for the sample with x = 0, which exhibits a multiphase structure with a predom inant alpha-Fe phase. The lattice constants a and c and the unit-cell volumes v of Sm2Fe17-xGaxC2 compounds with x greater than or equal to 2 increase monotonically with increasing Ga concentration. The Curie t emperature T-C and room-temperature saturation magnetization M(s) are found to decrease monotonically with increasing Ga concentration x fro m 635 to 338 K and from 102.3 to 29.0 emu g(-1) respectively, as x inc reases from 2 to 6. The Sm2Fe17-xGaxC2 compounds exhibit an easy c-axi s anisotropy. The room-temperature anisotropy field is 135 kOe for x = 2, which is about 55 kOe higher than that of Nd2Fe14B, and it decreas es to 60 kOe at x = 4.