Columnar Structure in FePt-C Granular Media for Heat-Assisted Magnetic Recording

B. S.D.C.S. Varaprasad; J. Wang; T. Shiroyama; Y. K. Takahashi; K. Hono

doi:10.1109/TMAG.2015.2435027

Columnar Structure in FePt-C Granular Media for Heat-Assisted Magnetic Recording

B. S.D.C.S. Varaprasad, J. Wang, T. Shiroyama, Y. K. Takahashi^*, K. Hono

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

30 Citations (Scopus)

Abstract

We attempted a compositionally graded sputtering process to overcome the phase separation in the growth direction in the FePt-C granular film in order to realize the columnar structure of FePt grains with an aspect ratio larger than 1.5. In order to overcome the problem of the formation of a second FePt-C layer for the thickness larger than 6 nm, we deposited the FePt-C film by changing the carbon concentration during the sputtering process. The formation of the second FePt-C layer was suppressed, which led to the growth of columnar grains with an aspect ratio of 1.5. The overall volume fraction of carbon is a decisive factor on the size of the FePt grains. Using the compositionally graded process, FePt-C nanogranular films with an average grain size of 7.8 nm, a thickness of 10 nm, and a perpendicular coercivity of 40 kOe were obtained.

Original language	English
Article number	7117424
Journal	IEEE Transactions on Magnetics
Volume	51
Issue number	11
DOIs	https://doi.org/10.1109/TMAG.2015.2435027
Publication status	Published - 2015 Nov 1
Externally published	Yes

Keywords

FePt-C
Heat Assisted Magnetic Recording
columnar structure
granular media

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials
Electrical and Electronic Engineering

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10.1109/TMAG.2015.2435027

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title = "Columnar Structure in FePt-C Granular Media for Heat-Assisted Magnetic Recording",

abstract = "We attempted a compositionally graded sputtering process to overcome the phase separation in the growth direction in the FePt-C granular film in order to realize the columnar structure of FePt grains with an aspect ratio larger than 1.5. In order to overcome the problem of the formation of a second FePt-C layer for the thickness larger than 6 nm, we deposited the FePt-C film by changing the carbon concentration during the sputtering process. The formation of the second FePt-C layer was suppressed, which led to the growth of columnar grains with an aspect ratio of 1.5. The overall volume fraction of carbon is a decisive factor on the size of the FePt grains. Using the compositionally graded process, FePt-C nanogranular films with an average grain size of 7.8 nm, a thickness of 10 nm, and a perpendicular coercivity of 40 kOe were obtained.",

keywords = "FePt-C, Heat Assisted Magnetic Recording, columnar structure, granular media",

author = "Varaprasad, {B. S.D.C.S.} and J. Wang and T. Shiroyama and Takahashi, {Y. K.} and K. Hono",

note = "Publisher Copyright: {\textcopyright} 1965-2012 IEEE.",

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language = "English",

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AU - Varaprasad, B. S.D.C.S.

AU - Wang, J.

AU - Shiroyama, T.

AU - Takahashi, Y. K.

AU - Hono, K.

PY - 2015/11/1

Y1 - 2015/11/1

N2 - We attempted a compositionally graded sputtering process to overcome the phase separation in the growth direction in the FePt-C granular film in order to realize the columnar structure of FePt grains with an aspect ratio larger than 1.5. In order to overcome the problem of the formation of a second FePt-C layer for the thickness larger than 6 nm, we deposited the FePt-C film by changing the carbon concentration during the sputtering process. The formation of the second FePt-C layer was suppressed, which led to the growth of columnar grains with an aspect ratio of 1.5. The overall volume fraction of carbon is a decisive factor on the size of the FePt grains. Using the compositionally graded process, FePt-C nanogranular films with an average grain size of 7.8 nm, a thickness of 10 nm, and a perpendicular coercivity of 40 kOe were obtained.

AB - We attempted a compositionally graded sputtering process to overcome the phase separation in the growth direction in the FePt-C granular film in order to realize the columnar structure of FePt grains with an aspect ratio larger than 1.5. In order to overcome the problem of the formation of a second FePt-C layer for the thickness larger than 6 nm, we deposited the FePt-C film by changing the carbon concentration during the sputtering process. The formation of the second FePt-C layer was suppressed, which led to the growth of columnar grains with an aspect ratio of 1.5. The overall volume fraction of carbon is a decisive factor on the size of the FePt grains. Using the compositionally graded process, FePt-C nanogranular films with an average grain size of 7.8 nm, a thickness of 10 nm, and a perpendicular coercivity of 40 kOe were obtained.

KW - FePt-C

KW - Heat Assisted Magnetic Recording

KW - columnar structure

KW - granular media

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Columnar Structure in FePt-C Granular Media for Heat-Assisted Magnetic Recording

Abstract

Keywords

ASJC Scopus subject areas

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