Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1612897 | Journal of Alloys and Compounds | 2013 | 8 Pages |
Abstract
Magnetic susceptibility, magnetization and neutron diffraction measurements have been performed to study structure and magnetic states of crystalline and amorphous Nd2Fe14B and Er2Fe14B alloys. In the crystalline state there exists a large (about 20%) anisotropy of Er-sublattice magnetization. Values of the magnetic anisotropy constant of Er ions and the Er-Fe exchange-coupling parameter were estimated using temperature dependence of the Er- and Fe-sublattice magnetizations. Amorphous state of the samples was obtained by irradiation of fast (Eeff ⩾ 1 ÐeV) neutrons with a fluence up to the 1.2 Ã 1020 n/Ñmâ2 at 340 K. It is shown that antiferromagnetic coupling between the rare-earth and iron spins is kept in the amorphous state. Amorphization of the samples is found to result in reduction of the Curie temperature (TC) by about 200 K and almost total absence of coercivity. We suggest that the strong decrease of TC is a consequence of enhancement of negative Fe-Fe interactions as a result of dispersion of interatomic distances, which is a characteristic feature of the amorphous state.
Keywords
Related Topics
Physical Sciences and Engineering
Materials Science
Metals and Alloys
Authors
A.E. Teplykh, Yu.G. Chukalkin, S. Lee, S.G. Bogdanov, N.V. Kudrevatykh, E.V. Rosenfeld, Yu.N. Skryabin, Y. Choi, A.V. Andreev, A.N. Pirogov,