Nanostructure and magnetic properties of FePt

C cluster films

Yingfan Xu, M. L. Yan, David J Sellmyer

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

Magnetic properties and nanostructure of FePt: C cluster-deposited films with C volume fraction of 7%, 14%, 33%, and 45% have been studied. As-deposited FePt: C films were prepared by a multilayer method in which FePt layers were deposited from a cluster source employing a gas-aggregation technique and C layers from a normal sputtering gun. In the as-deposited films, FePt clusters with fcc structure are embedded in the C matrix. The high anisotropy FePt L10 cluster structure was realized in the films via post-deposition annealing and the nanostructure of the films was observed by high-resolution transmission electron microscope (TEM). The results for a film with 45 vol. % C showed that FePt clusters are well separated by C matrix and the cluster diameter is about 4.5 nm. The coercivity increases with increase of annealing temperature; coercivities larger than 9 kOe were achieved in the films after annealing at a temperature of 700°C and above. Magnetization reversal of the films was studied by moment-decay measurements and the data were fitted with the Sharrock formula. For the film with 45 vol. % C annealed at 625°C, the thermal stability factor KUV*/kB, T activation volume V*, and anisotropy constant Ku are 231, 0.83 × 101-18cm3 and 1.2 × 107 erg/cm 3, respectively.

Original languageEnglish (US)
Pages (from-to)2525-2527
Number of pages3
JournalIEEE Transactions on Magnetics
Volume40
Issue number4 II
DOIs
StatePublished - Jul 1 2004

Fingerprint

Nanostructures
Magnetic properties
magnetic properties
Annealing
Coercive force
annealing
coercivity
Anisotropy
Magnetization reversal
anisotropy
matrices
Sputtering
Volume fraction
Multilayers
Thermodynamic stability
thermal stability
Electron microscopes
Agglomeration
electron microscopes
Gases

Keywords

  • FePt
  • High anisotropy
  • L1 structure
  • Nanocluster
  • Thermal stability

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Physics and Astronomy (miscellaneous)

Cite this

Nanostructure and magnetic properties of FePt : C cluster films. / Xu, Yingfan; Yan, M. L.; Sellmyer, David J.

In: IEEE Transactions on Magnetics, Vol. 40, No. 4 II, 01.07.2004, p. 2525-2527.

Research output: Contribution to journalArticle

Xu, Yingfan ; Yan, M. L. ; Sellmyer, David J. / Nanostructure and magnetic properties of FePt : C cluster films. In: IEEE Transactions on Magnetics. 2004 ; Vol. 40, No. 4 II. pp. 2525-2527.
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