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Non-stoichiometric FePt nanoclusters for heated dot magnetic recording media
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Nonstoichiometric FePt nanoclusters for heated dot magnetic recording media [Published title]
Citation
Mohan, J. R., Rohit Medwal, Surbhi Gupta, Kriti Gogia, Vas, J. V., Rekha Gupta, Angshuman Deka, Rawat, R. S., Annapoorni Subramanian, & Fukuma, Y. (2021). Nonstoichiometric FePt nanoclusters for heated dot magnetic recording media. ACS Applied Nano Materials, 4(7), 7079-7085. https://doi.org/10.1021/acsanm.1c01085
Author
Mohan, John Rex
•
Rohit Medwal
•
Surbhi Gupta
•
Kriti Gogia
•
Vas, Joseph Vimal
•
Rekha Gupta
•
Angshuman Deka
•
•
Annapoorni Subramanian
•
Fukuma, Yasuhiro
Abstract
Heated dot magnetic recording (HDMR) provides a path to increase the areal density of magnetic recording media beyond 4 Tb/in2. HDMR-based recording media requires ultrasmall, noninteracting, and thermally stable magnetic dots with high perpendicular anisotropy. We have synthesized nonstoichiometric Fe60Pt40 nanoclusters with and without a Pt buffer layer on silicon substrates, which shows a reduction in chemical ordering temperatures. The Fe60Pt40 nanoclusters retain the hard magnetic phase up to 1023 K with the coercive field of 1.3 Tesla due to the Pt element compensation from the buffer layer. This compensation of Pt was confirmed through X-ray diffraction (XRD) investigations where two distinct phases of Fe3Pt and FePt3 are observed at elevated annealing temperatures. Micromagnetic simulations were performed to understand the effect of magnetic anisotropy, dipolar interaction, and exchange coupling between the soft magnetic Fe3Pt and hard magnetic FePt. The results imply that nonstoichiometric Fe60Pt40 with the Pt buffer layer facilitates low chemical ordering temperatures retaining the high perpendicular anisotropy with minimal noninteracting behavior, suitable for HDMR.
Date Issued
2021
Journal
ACS Applied Nano Material
DOI
10.1021/acsanm.1c01085
Grant ID
KAKENHI No. 18H01862
KAKENHI No. 18H05953
MOE2017-T2-2-129
NRF-CRP21-2018-0003
MOE2019-T2-1-058
Funding Agency
JSPS Grant-in-Aid
Nippon Sheet Glass Foundation
Ministry of Education, Singapore