Structural phase transition and ferromagnetism in monodisperse 3 nm FePt particles

TitleStructural phase transition and ferromagnetism in monodisperse 3 nm FePt particles
Publication TypeJournal Article
Year of Publication2007
AuthorsRong CB, Poudyal N, Chaubey GS, Nandwana V, Skomski R, Wu YQ, Kramer MJ, Liu JP
Journal TitleJournal of Applied Physics
Volume102
Pages043913
Date PublishedAug
Type of ArticleArticle
ISBN Number0021-8979
Accession NumberISI:000249156200075
Keywordsdependence, films, L1(0)-FEPT NANOPARTICLES, MAGNETS
Abstract

FePt nanoparticles with a size of 3 nm and thermally stable room-temperature ferromagnetism are investigated. The monodisperse nanoparticles were prepared by chemical synthesis and a salt-matrix annealing technique. Structural and magnetic characterizations confirmed the phase transition from the disordered face-centered cubic structure to the L1(0) structure with the chemical ordering parameter of 0.62 +/- 0.05. Analysis in blocking temperature and fitting of temperature dependence of switching field reveals that the transformed 3 nm nanoparticles have a magnetic anisotropy constant of (2.8 +/- 0.2)x10(6) J/m(3), smaller than those for the bigger particles and the fully ordered L1(0) bulk phase. (C) 2007 American Institute of Physics.

DOI10.1063/1.2773694
Alternate JournalJ. Appl. Phys.