MAGNETIC-PROPERTIES OF SM2(FE1-XGAX)17 COMPOUNDS (X=0-0.5)

Sm2(Fe1-xGax)17 (X=0-0.5) compounds were prepared by arc melting. X-ra y diffraction patterns showed that all compounds were single phase wit h rhombohedral Th2Zn17-type structure. X-ray diffraction patterns of t he aligned samples showed that the alloys with x=0.15, 0.20 and 0.25 h ave uniaxial anisotropy at room temperature. The spin reorientation tr ansition temperatures were measured by a superconducting quantum inter ference device (SQUID) and a magnetic balance. A tentative phase diagr am was constructed. The substitution of Ga for Fe leads to an increase in the reorientation temperature and the lattice constants. The Curie temperature increases with the Ga concentration, and achieves a maxim um at x=0.2, then decreases. The saturation magnetization decreases mo notonically with Ga concentration. The coupling constants A(TT) and A( RT) were derived using a mean molecular field model. A(TT) reaches a m aximum at x=0.3 and then decreases with x, but A(RT) is almost unchang ed with varying x.