Metallic glass thin films for patterned recording media

• Project/Area Number: 22760002
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Single-year Grants
• Research Field: Applied materials science/Crystal engineering
• Research Institution: Tohoku University
• Principal Investigator: SHARMA Parmanand 東北大学, 金属材料研究所, 助教 (80451623)
• Research Collaborator: WANG Yaocen 東北大学, 超低損失ナノ結晶軟磁性材料研究開発センター, 研究支援者
• Project Period (FY): 2010 – 2012
• Project Status: Completed (Fiscal Year 2012)
• Budget Amount: ¥4,030,000 (Direct Cost: ¥3,100,000、Indirect Cost: ¥930,000); Fiscal Year 2012: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2011: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2010: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
• Keywords: 金属ガラス / 磁性 / L10-FePt / 薄膜

Research Abstract

This project demonstrated the feasibility of exchange-coupled patterned magnetic recording media consisting of metallic glass as a soft magnetic under-layer and FePt as a hard magnetic layer. We found that the CoFeTaB and FeHfNbYB soft magnetic metallic glass thin films can be used as a soft magnetic underlayer. Both CoFeTaB and FeHfNbYB have sufficiently large super-cooled liquid region, therefore they can be patterned using nano-impriniting techniques. These metallic glass underlayers promote growth of L10 FePt along preferred (111) crystallographic direction. Pattern size ranging from 25 μm to 20 nm were made from L10 FePt (111)/soft magnetic metallic glass by photo/electron beam lithography. Both lift-off and Ar-ion etching techniques were used. It is found that the lift-off technique faces problem when size of the dots reached below 100 nm. Magnetic force microscopy showed a clear transition from single domain to multidomain as the size of the FePt/soft magnetic metallic glass dot increases above 300 nm. It can be concluded that the (111) L10FePt/softmagnetic metallic bilayered structure has a large potential in fabrication of ultrahigh density patterned recoding media.

Research Products

• [Journal Article] 2013 (2013)
  • Author(s): P. Sharma, N. Kaushik, M. Esashi, M. Nishijima and A. Makino
  • Journal Title: Journal of Magnetism and Magnetic Materials Volume: Vol.38 Pages: 337-338
  • DOI: 10.1016/j.jmmm.2013.02.029
  • Peer Reviewed
• [Journal Article] Magnetization reversal in a preferred oriented (111) L10 FePt grown on a soft magnetic metallic glass for tilted magnetic recording (2012)
  • Author(s): Y. Wang, P. Sharma and A. Makino
  • Journal Title: Journal of Physics: Condensed Matter Volume: Vol. 24 Issue: 7 Pages: 76004-76004
  • DOI: 10.1088/0953-8984/24/7/076004
  • Peer Reviewed
• [Journal Article] L10 FePt(111)/glassyCoFeTaB bilayered structure for patterned media (2011)
  • Author(s): P. Sharma, N. Kaushik, A. Makino, M.Esashi and A. Inoue
  • Journal Title: Journal of Applied Physics Volume: Vol. 109 Issue: 7
  • DOI: 10.1063/1.3561803
• [Journal Article] Anomalous temperature dependence of coercivity at low temperature in L10 FePt thin films (2011)
  • Author(s): P. Sharma, N. Kaushik, A. Makino and A. Inoue
  • Journal Title: IEEE Transactions on Magnetics Volume: Vol. 47 (10) Issue: 10 Pages: 4394-4394
  • DOI: 10.1109/tmag.2011.2159366
• [Journal Article] L1_0 FePt(111)/glassy CoFeTaB bilayered structure for patterned media (2011)
  • Author(s): Kaushik, Sharma, etal
  • Journal Title: Journal of Applied Physics Volume: Vol.109
• [Journal Article] Domain wall assisted magnetization switching in (111) oriented L10 FePt grown on a soft magnetic metallic glass (2010)
  • Author(s): Kaushik, Sharma, etal
  • Journal Title: Appl.Phys.Letts. Volume: Vol.97 Pages: 72510-72510
• [Presentation] Fabrication and magnetic properties of L10 FePt thin films for tilted magnetic recording media (2011)
  • Author(s): P. Sharma, Y. Wang, A. Makino
  • Organizer: JIM 2011 Autumn Meeting, Ginowan, Okinawa
  • Place of Presentation: Japan
  • Year and Date: 2011-11-07
• [Presentation] Fabrication and magnetic properties of L10 FePt thin films for tilted magnetic recording media (2011)
  • Author(s): P.Sharma, Y.Wang, A.Makino
  • Organizer: JIM 2011 autumn meeting
  • Place of Presentation: Ginowan, Okinawa
  • Year and Date: 2011-11-07
• [Presentation] L1_0 FePt(111)/glassy CoFeTaB bilayered structure for patterned media (2010)
  • Author(s): Parmanand Sharma, Neelam Kaushik, etal.
  • Organizer: 55th Magnetism and Magnetic Materials (MMM) conference, 2010
  • Place of Presentation: Atlanta, USA
  • Year and Date: 2010-11-16
• [Presentation] Study of magnetic easy axis in L10 FePt (111)/CoFeTaB/SiO2/Si tilted system for perpendicular recording (2010)
  • Author(s): Parmanand Sharma, Akihiro Makino, Akihisa Inoue
  • Organizer: JIM Autumn Meeting, 2010
  • Place of Presentation: Sapporo, Japan
  • Year and Date: 2010-09-27
• [Presentation] L10 FePt(111)/glassy CoFeTaB bilayered structure for patterned media (2010)
  • Author(s): P. Sharma, N. Kaushik, A. Makino, M.Esashi and A. Inoue
  • Organizer: 55th Magnetism and Magnetic Materials (MMM) conference
  • Place of Presentation: Atlanta, USA
• [Presentation] Study of magnetic easy axis in L10 FePt (111)/CoFeTaB/SiO2/Si tilted system forperpendicular recording (2010)
  • Author(s): P. Sharma, A. Makino and A. Inoue
  • Organizer: JIM Autumn Meeting
  • Place of Presentation: Sapporo, Japan
• [Presentation] Application of metallic glass thin films in development of patterned magnetic recording media (2010)
  • Author(s): P. Sharma, N. Kaushik, K. Yubuta, A. Makino and A. Inoue
  • Organizer: ISMANAM
  • Place of Presentation: Zurich, Switzerland