Effect of MgO underlayer misorientation on the texture and magnetic property of FePt-C granular film

J. Wang; S. Hata; Y. K. Takahashi; H. Sepehri-Amin; B. S.D.Ch S. Varaprasad; T. Shiroyama; T. Schrefl; K. Hono

doi:10.1016/j.actamat.2015.03.007

Effect of MgO underlayer misorientation on the texture and magnetic property of FePt-C granular film

J. Wang, S. Hata, Y. K. Takahashi, H. Sepehri-Amin, B. S.D.Ch S. Varaprasad, T. Shiroyama, T. Schrefl, K. Hono^*

^*Corresponding author for this work

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

44 Citations (Scopus)

Abstract

A transmission electron microscope (TEM) based orientation mapping technique and micromagnetic simulations were applied to study the influence of easy axis distribution (EAD) on magnetic properties of FePt-C granular films which were deposited on a single crystalline MgO (0 0 1) substrate and a (0 0 1)-textured poly-crystalline MgO underlayer. The FePt-C film on the polycrystalline MgO underlayer shows smaller perpendicular coercivity, broader switching field distribution and visible in-plane minor loop compared with that deposited on the single crystalline MgO (0 0 1) substrate. Although the grain sizes and their distributions in both films look similar in TEM, orientation mapping and texture analysis revealed that the polycrystalline MgO underlayer introduces significant misorientation in the (0 0 1)-textured FePt grains. Micromagnetic simulations successfully reproduced the large hysteresis in the in-plane magnetization by introducing the specific misorientation distribution of the FePt grains obtained from the texture analysis. The misoriented FePt grains were found to be grown from misoriented MgO grains, indicating that the improvement of the (0 0 1) texture of the MgO underlayer is essential to reduce the in-plane component of FePt based recording media.

Original language	English
Pages (from-to)	41-49
Number of pages	9
Journal	Acta Materialia
Volume	91
DOIs	https://doi.org/10.1016/j.actamat.2015.03.007
Publication status	Published - 2015 Jun 1
Externally published	Yes

Keywords

FePt-C
Heat assisted magnetic recording
Magnetic recording media
Misorientation

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials
Ceramics and Composites
Polymers and Plastics
Metals and Alloys

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10.1016/j.actamat.2015.03.007

Cite this

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title = "Effect of MgO underlayer misorientation on the texture and magnetic property of FePt-C granular film",

abstract = "A transmission electron microscope (TEM) based orientation mapping technique and micromagnetic simulations were applied to study the influence of easy axis distribution (EAD) on magnetic properties of FePt-C granular films which were deposited on a single crystalline MgO (0 0 1) substrate and a (0 0 1)-textured poly-crystalline MgO underlayer. The FePt-C film on the polycrystalline MgO underlayer shows smaller perpendicular coercivity, broader switching field distribution and visible in-plane minor loop compared with that deposited on the single crystalline MgO (0 0 1) substrate. Although the grain sizes and their distributions in both films look similar in TEM, orientation mapping and texture analysis revealed that the polycrystalline MgO underlayer introduces significant misorientation in the (0 0 1)-textured FePt grains. Micromagnetic simulations successfully reproduced the large hysteresis in the in-plane magnetization by introducing the specific misorientation distribution of the FePt grains obtained from the texture analysis. The misoriented FePt grains were found to be grown from misoriented MgO grains, indicating that the improvement of the (0 0 1) texture of the MgO underlayer is essential to reduce the in-plane component of FePt based recording media.",

keywords = "FePt-C, Heat assisted magnetic recording, Magnetic recording media, Misorientation",

author = "J. Wang and S. Hata and Takahashi, {Y. K.} and H. Sepehri-Amin and Varaprasad, {B. S.D.Ch S.} and T. Shiroyama and T. Schrefl and K. Hono",

note = "Funding Information: This work was supported in part by the Advanced Storage Technology Consortium (ASTC) of the International Disk Drive Equipment and Materials Association (IDEMA), USA, and the Grant-in-Aid (B) (Grant No. 26289232 ). The MEXT/JSPS Kakenhi ( 22102002 , 25286027 ). ASTARTM analysis was performed at the Ultramicroscopy Research Center, Kyushu University. Publisher Copyright: {\textcopyright} 2015 Acta Materialia Inc.",

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doi = "10.1016/j.actamat.2015.03.007",

language = "English",

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T1 - Effect of MgO underlayer misorientation on the texture and magnetic property of FePt-C granular film

AU - Wang, J.

AU - Hata, S.

AU - Takahashi, Y. K.

AU - Sepehri-Amin, H.

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

AU - Shiroyama, T.

AU - Schrefl, T.

AU - Hono, K.

N1 - Funding Information: This work was supported in part by the Advanced Storage Technology Consortium (ASTC) of the International Disk Drive Equipment and Materials Association (IDEMA), USA, and the Grant-in-Aid (B) (Grant No. 26289232 ). The MEXT/JSPS Kakenhi ( 22102002 , 25286027 ). ASTARTM analysis was performed at the Ultramicroscopy Research Center, Kyushu University. Publisher Copyright: © 2015 Acta Materialia Inc.

PY - 2015/6/1

Y1 - 2015/6/1

N2 - A transmission electron microscope (TEM) based orientation mapping technique and micromagnetic simulations were applied to study the influence of easy axis distribution (EAD) on magnetic properties of FePt-C granular films which were deposited on a single crystalline MgO (0 0 1) substrate and a (0 0 1)-textured poly-crystalline MgO underlayer. The FePt-C film on the polycrystalline MgO underlayer shows smaller perpendicular coercivity, broader switching field distribution and visible in-plane minor loop compared with that deposited on the single crystalline MgO (0 0 1) substrate. Although the grain sizes and their distributions in both films look similar in TEM, orientation mapping and texture analysis revealed that the polycrystalline MgO underlayer introduces significant misorientation in the (0 0 1)-textured FePt grains. Micromagnetic simulations successfully reproduced the large hysteresis in the in-plane magnetization by introducing the specific misorientation distribution of the FePt grains obtained from the texture analysis. The misoriented FePt grains were found to be grown from misoriented MgO grains, indicating that the improvement of the (0 0 1) texture of the MgO underlayer is essential to reduce the in-plane component of FePt based recording media.

AB - A transmission electron microscope (TEM) based orientation mapping technique and micromagnetic simulations were applied to study the influence of easy axis distribution (EAD) on magnetic properties of FePt-C granular films which were deposited on a single crystalline MgO (0 0 1) substrate and a (0 0 1)-textured poly-crystalline MgO underlayer. The FePt-C film on the polycrystalline MgO underlayer shows smaller perpendicular coercivity, broader switching field distribution and visible in-plane minor loop compared with that deposited on the single crystalline MgO (0 0 1) substrate. Although the grain sizes and their distributions in both films look similar in TEM, orientation mapping and texture analysis revealed that the polycrystalline MgO underlayer introduces significant misorientation in the (0 0 1)-textured FePt grains. Micromagnetic simulations successfully reproduced the large hysteresis in the in-plane magnetization by introducing the specific misorientation distribution of the FePt grains obtained from the texture analysis. The misoriented FePt grains were found to be grown from misoriented MgO grains, indicating that the improvement of the (0 0 1) texture of the MgO underlayer is essential to reduce the in-plane component of FePt based recording media.

KW - FePt-C

KW - Heat assisted magnetic recording

KW - Magnetic recording media

KW - Misorientation

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VL - 91

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EP - 49

JO - Acta Materialia

JF - Acta Materialia

ER -

Effect of MgO underlayer misorientation on the texture and magnetic property of FePt-C granular film

Abstract

Keywords

ASJC Scopus subject areas

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