Effect of oxygen stoichiometry on microstructural and magnetic properties of FePt/TaOxbilayer fabricated by ion-beam-bombardment deposition

G. J. Li, Chi Wah Leung, Y. C. Chen, J. H. Hsu, A. C. Sun, K. W. Lin, Philip W.T. Pong

Research output: Journal article publicationJournal articleAcademic researchpeer-review

4 Citations (Scopus)


The effect of TaOxcapping layer on microstructures and magnetic properties of FePt thin films via annealing was studied. The structural ordering of FePt from face-centered cubic to face-centered tetragonal phases depends strongly on the oxygen contents in the capping TaOxlayer. The role of the TaOxlayer is used to separate the FePt grains, as revealed by TEM. The annealed FePt/TaOx(15%O2/Ar) exhibited the largest out-of-plane coercivity (Hc4.2 kOe) amongst all samples, compared to that (∼2.4 kOe) in the reference FePt layer. At low oxygen content in FePt/TaOxbilayers, the Ta atoms may act as defects to obstruct the FePt ordering whereas at high oxygen contents, the excess oxygen atoms diffuse into the FePt layer and react with Fe to form iron oxides which give rise to the low coercivities, as characterized by the XPS depth profile and binding energy analysis.
Original languageEnglish
Article number6559126
Pages (from-to)3310-3313
Number of pages4
JournalIEEE Transactions on Magnetics
Issue number7
Publication statusPublished - 2 Aug 2013


  • FePt
  • ion-beam bombardment
  • magnetic properties

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Electrical and Electronic Engineering

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