FePt thin films are deposited on SrTiO3, MgO, and a 2 nm-FeOx underlayer on an Si substrate at room temperature and then annealed at elevated temperatures. Studies of the L10 ordering process in each case show that the ordering temperature for the FePt film on the nonepitaxial Si/FeOx substrate is ∼150 °C lower than the epitaxial FePt films deposited on MgO and SrTiO3 substrates. We argue that internal stresses arising from lattice defects and a recrystallizing process as well as thermal strain from differences in thermal expansion between substrate and film are responsible for the differences in ordering kinetics from the A1 to L10 phase of FePt on the various substrates.
Bibliographical noteFunding Information:
The first author would like to thank Dr. B. Lu of Seagate Research for helpful discussions. The authors would like to thank Dr. J. Åkerman for carefully reading this manuscript and the reviewer(s) for modifying this manuscript thoroughly. This work was supported in part by the National Nature Science Foundation under Grant 60490290 and Grant 60678008 from the Science and Technology Committee of Shanghai under Grant 06DJ14007.
- Epitaxial growth
- Nonepitaxial growth
- Ordering kinetics