Characterization of L1 0-FePt/Fe based exchange coupled composite bit pattern media

Hao Wang, Weimin Li, M. Tofizur Rahman, Haibao Zhao, Jun Ding, Yunjie Chen, Jian Ping Wang

Research output: Contribution to journalArticlepeer-review

10 Scopus citations


L1 0-FePt exchange coupled composite (ECC) bit patterned media has been considered as a potential candidate to achieve high thermal stability and writability for future high density magnetic recording. In this paper, FePt based ECC bit patterned structures with 31 nm bit size and 37 nm pitch size were fabricated using di-block copolymer lithography on 3 inch wafer. Remanant states were tracked using magnetic force microscopy (MFM). DC demagnetization (DCD) curves were plotted by counting the reversed bits in the MFM images. Magnetic domains in which the magnetizations of the neighboring bits were aligned to the same direction were observed in the MFM patterns. Thermal decay measurement was performed for the samples to obtain the thermal stability and gain factor. The thermal barrier was found around 210 k BT with a gain factor up to 1.57 for the bit patterned structure FePt(4 nm)/Fe(4 nm).

Original languageEnglish (US)
Article number07B914
JournalJournal of Applied Physics
Issue number7
StatePublished - Apr 1 2012

Bibliographical note

Funding Information:
The authors are grateful for the support by Dr. Y. Isowaki, Dr. Y. Kamata, and Dr. A. Kikitsu from Toshiba Corporation for the di-block copolymer patterning processing. The work was partially supported by INSIC EHDR program and WDC. Parts of this work were carried out in the Characterization Facility, University of Minnesota, a member of the NSF-funded Materials Research Facilities Network ( ) via the NSF MRSEC program under Award No. DMR-0819885.


Dive into the research topics of 'Characterization of L1 0-FePt/Fe based exchange coupled composite bit pattern media'. Together they form a unique fingerprint.

Cite this