Abstract
A series of 20 and 100 nm Fe53Pt47 thin films sputter-deposited onto Si substrates have been thermally annealed using a pulsed thermal plasma arc lamp. A series of one, three or five pulses were applied to the thin films with widths of either 50 or 100 ms. The microstructure and magnetic properties of these annealed Fe53Pt47 films are discussed according to the various annealing conditions and A1 to L10 phase transformation. Upon pulse annealing, the average in-plane grain size of 15 nm (nearly equivalent for both film thicknesses) was observed to increase to values near 20 nm. In general, increasing the pulse width or number of pulses increased the L10 order parameter, tetragonality of the c/a ratio and coercivity of the specimen. The exception to this trend was for five pulses at 100 ms for both film thicknesses, which indicated a reduction of the order parameter and coercivity. This reduction is believed to be a result of the interdiffusion of Fe and Pt into the Si substrate and the formation of iron oxide clusters in the grain boundaries characterized by atom probe tomography.
Original language | English |
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Pages (from-to) | 2451-2458 |
Number of pages | 8 |
Journal | Journal of Magnetism and Magnetic Materials |
Volume | 321 |
Issue number | 16 |
DOIs | |
State | Published - Aug 2009 |
Funding
The authors gratefully recognize the Center for Materials for Information Technology at the University of Alabama and the National Science Foundation (NSF-DMR-0529369) for supporting this research. The ORNL lamp research is sponsored by the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory managed by UT-Battelle, LLC for the US Department of Energy. The TEM and laser on the LEAP were acquired through the NSF major instrumentation Grant NSF-DMR-0421376 and NSF-DMR-0722631, respectively.
Keywords
- FePt
- L1 ordering
- Rapid thermal annealing