1. Temperature dependence of the anisotropy field of L10 FePt near the Curie temperature.
- Author
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Richter, H. J. and Parker, G. J.
- Subjects
- *
CURIE temperature , *SCALING laws (Nuclear physics) , *MAGNETIZATION , *MAGNETIC anisotropy , *DATA tapes - Abstract
Near the Curie temperature, the anisotropy field of magnetically uniaxial L10 FePt is expected to follow the scaling law (1 – T/Tc)β, where T is the temperature and Tc is the Curie temperature. In the literature, β values between 0.36 and 0.65 have been reported. Based on recording measurements and micromagnetic analysis, we show that only the values of β near the low end of the reported range are compatible with the data. We also conclude that thermally activated magnetization reversal at temperatures near Tc cannot be ignored, even at time scales smaller than 1 ns. We demonstrate that thermally activated magnetization reversal at temperatures close to Tc is well described by conventional theory with a frequency factor f0 of the order of 1012 Hz. It is reasoned that the unusually high value for f0 is a consequence of the temperature-induced reduction of the degree of alignment of the micro-spins within the grains. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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