In conventional magnetic recording media fabrication processes, magnetically soft regions of composite or graded material are prepared by varying either the substrate temperature or the film composition during deposition. In this work, ultrathin FePt granular media with graded composition was fabricated directly by spontaneous layer diffusion between FePt and Pt layers during the film deposition. Electron energy loss spectroscopy analysis on individual FePt columnar grains identified the composition distribution of Fe and confirmed the Fe composition gradient. A large gain factor of 3.74, indicative of a relatively high-thermal energy barrier, was obtained in this spontaneously formed FePt graded granular media.
Bibliographical noteFunding Information:
Parts of this work were carried out in the Characterization Facility (Charfac), University of Minnesota, a member of the NSF-funded Materials Research Facilities Network (www.mrfn.org) via the NSF MRSEC program under award number DMR-0819885. The authors would like to thank the partial support from INSIC EHDR program and Western Digital.
- Diffusion process
- Exchange coupled composite (ECC) media
- Gain factor
- Graded media
- Information storage
- Magnetic recording