Intra-cluster exchange-coupled high-performance permanent magnets

TitleIntra-cluster exchange-coupled high-performance permanent magnets
Publication TypeJournal Article
Year of Publication2008
AuthorsRui X, Shield JE, Sun Z, Skomski R, Xu Y, Sellmyer DJ, Kramer MJ, Wu YQ
Journal TitleJournal of Magnetism and Magnetic Materials
Date PublishedNov
Type of ArticleArticle
ISBN Number0304-8853
Accession NumberISI:000258395400007
Keywordscluster, CONDENSATION, energy product, exchange-spring, films, HIGH-ENERGY PRODUCTS, inert gas, L1(0) FEPT, magnetic material, microstructure, multilayers, nanoparticles, TRANSMISSION ELECTRON-MICROSCOPE

Inert gas condensation has been used to produce Fe-rich Fe-Pt clusters imbedded in C or SiO2. Compositions of the clusters ranged from the single-phase Fe3Pt phase field to the single-phase FePt phase field, and included compositions in the two-phase Fe3Pt + FePt phase field. The as-formed clusters formed in the A1 fcc structure for all compositions, and after proper heat treatment transformed to the Fe3Pt and/or FePt phases, depending on composition. Because the clusters were well isolated, the scale of the phases was limited by the cluster size. This intracluster structuring on such a. ne scale ensured that the soft Fe3Pt and hard FePt phases were fully magnetically exchange-coupled with each other, which allowed greater soft phase fractions comparing with previous work. Energy products of the two-phase clusters with 50% Fe3Pt exceeded 25MGOe, compared to 11.8MGOe for the single-phase FePt clusters. Micromagnetic simulations revealed remarkable similarities with the experimental results with respect to the relationship between both coercivity and energy product as a function of cluster composition. Published by Elsevier B.V.

Alternate JournalJ. Magn. Magn. Mater.