Curie temperature of FePt:B2O3 nanocomposite films

H. Zeng, Renat F Sabirianov, O. Mryasov, M. L. Yan, K. Cho, David J Sellmyer

Research output: Contribution to journalArticlepeer-review

53 Scopus citations

Abstract

We report results on experimental and theoretical studies of structural and magnetic properties of FePt:B2O3 nanocomposite films. It was found for films prepared by magnetron sputtering with subsequent annealing that lattice parameters a and c of fct FePt change with significantly different rates with increase of the B2O3 fraction. As a consequence, fundamental magnetic properties change markedly, with the Curie temperature decreasing by 36% for 25% FePt volume fraction compared with the bulk value. Using an ab initio parametrization of magnetic interactions, we propose statistical model of thermal fluctuations in fct FePt, which explains these observations. Our modeling results demonstrate that the observed phenomena originate in the variation of the exchange interaction parameters with the changes in the c/a ratio. We find that the main factor of this variation is the increase of the difference between the in-plane and interplane exchange interactions as c/a decreases from its bulk value due to stress exerted by the B2O3 matrix.

Original languageEnglish (US)
Article number184425
Pages (from-to)1844251-1844256
Number of pages6
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume66
Issue number18
StatePublished - Nov 1 2002

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

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