Critical bond lengths and their role in spontaneous magnetostriction of R2Fe17CX(R = Y, Nd, Gd, Tb, Er)

TitleCritical bond lengths and their role in spontaneous magnetostriction of R2Fe17CX(R = Y, Nd, Gd, Tb, Er)
Publication TypeJournal Article
Year of Publication2007
AuthorsYang N, Dennis KW, McCallum RW, Kramer MJ, Zhang Y, Lee PL
Journal TitleJournal of Magnetism and Magnetic Materials
Volume311
Pages630-638
Date PublishedApr
Type of ArticleArticle
ISBN Number0304-8853
Accession NumberISI:000245495700025
Keywordscarbides, magnetostriction, MOSSBAUER, neutron-diffraction, rare-earth transition-metal compound, rietveld refinement, synchrotron, THERMAL-EXPANSION, transition, X-ray powder diffraction
Abstract

High-energy high-flux synchrotron X-rays have been used to study the spontaneous magnetostriction of R2Fe17 (R = Y, Nd, Gd, Tb, Er) and their carbides in the temperature range 10-1100 K. Addition of interstitial carbon greatly increases both the Curie temperatures (T-C) and the spontaneous magnetostrain of the compounds, while reduces the anisotropy of the magnetostrain by expanding the distances between rare-earth and neighboring Fe sites. The increase of T-C with carbon is due to the increased spatial separation of the Fe hexagon layers. On the basal plane, the Fe hexagons are squeezed and the contribution of Fe sublattice to spontaneous magnetostriction is attenuated, while that of rare-earth sublattice is enhanced. The average bond magnetostrain around Fe sites are in linear relation with their hyperfine field intensities. (C) 2006 Elsevier B.V. All rights reserved.

DOI10.1016/j.jmmm.2006.08.026
Alternate JournalJ. Magn. Magn. Mater.