Effect of Ga substitution on the Sm sublattice anisotropy in Sm2Fe17-xGax (0 <= x <= 8)

In order to study the unique behavior of the Sm sublattice anisotropy, magn etization curves along both the easy and hard directions were obtained at 1 0 K for Sm2Fe17-xGax (0 less than or equal to x less than or equal to 8) po wders which were aligned using either static- or dynamic-field alignment me thods. The Fe sublattice contribution was isolated by making similar measur ements on Y2Fe17-xGax (0 less than or equal to x less than or equal to 8), as the presence of Y eliminates the rare-earth sublattice contribution. The results show that the Sm sublattice anisotropy is dominant for x greater t han or equal to 1. It increases with increasing Ga content, reaching a (bro ad) maximum of 1.8X10(7) erg/cm(3) for x approximate to 2-3, and then decre ases and becomes negative for x approximate to 5.5. This work shows that th e unique behavior of the magneto-crystalline anisotropy for Sm2Fe17-xGax ar ises from the variation of the Sm-sublattice contribution with Ga substitut ion. (C) 1999 American Institute of Physics. [S0021-8979(99)56208-7].