EFFECTS OF AL SUBSTITUTIONS ON THE MAGNETIC-ANISOTROPY OF SM2FE17 COMPOUNDS

Compounds in the series Sm2Fe17-xAlx have been investigated. Samples with x = 0, 1, 2, 3 and 4 have been shown to be single phased With the Th2Zn17 StruCture. The Curie temperature is found to increase from T(C) = 391 K for the x = 0 sample to T(C) = 471 K for the x = 3 sample. Further substitution of Al for Fe decrease T(C). X-ray diffraction studies of magnetic-field-oriented powders showed that alloys with x < 2 exhibit easy plane anisotropy while samples with x > 2 exhibit easy axis anisotropy. The x = 2 sample showed a mixture of easy plane and easy axis behaviour. This observation represents the first case of clear evidence for room temperature uniaxial anisotropy in the R2Fe17 compounds without the addition of interstitial nitrogen or carbon.