THE EFFECTS OF HIGH-ENERGY MILLING ON THE STRUCTURAL AND HYPERFINE PROPERTIES OF YFE2

Mossbauer spectroscopy, X-ray diffraction and nuclear magnetic resonan ce have been used to study the effects of severe milling on the atomic and magnetic properties of the ferromagnetic intermetallic Laves phas e compound YFe2. The Mossbauer effect and nuclear magnetic resonance w ere carried out on the Fe site and on the Y site, respectively. Consis tently, after 30 h of milling, the results indicate that the milling p rocess induces structure and atomic disorder. The X-ray diffraction pa ttern shows no crystalline reflection planes, indicating that the stru cture is amorphous within the experimental resolution. The Curie tempe rature reduces from 542 K to less than 100 K after 50 h milling, altho ugh at 4.2 K the average Fe-57 magnetic hyperfine field value remains near the same as in the original crystalline compound.