Oxygen-stoichiometry-dependent microstructural and magnetic properties of CoPt thin films capped with ion-beam-assisted deposited TiOx layers

Guijun Li; Chi Wah Leung; Chin Shueh; Yi Jing Wu; Ko Wei Lin; An Cheng Sun; Jen Hwa Hsu; Pui To Lai; Philip W.T. Pong

doi:10.1016/j.surfcoat.2012.05.103

Oxygen-stoichiometry-dependent microstructural and magnetic properties of CoPt thin films capped with ion-beam-assisted deposited TiO_x layers

Guijun Li, Chi Wah Leung, Chin Shueh, Yi Jing Wu, Ko Wei Lin, An Cheng Sun, Jen Hwa Hsu, Pui To Lai, Philip W.T. Pong

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

4 Scopus citations

Abstract

The magnetic properties of CoPt with different percentages of oxygen in the TiO_x capping layer were investigated through annealing processes. Results have shown that after annealing, the structural phase transformation from fcc to fct CoPt occurred and was confirmed by the enhanced coercivities. In addition, the isolated CoPt grains separated by grain boundary TiO_x in the annealed CoPt/TiO_x (30% O₂/Ar) thin films exhibited the largest coercivity. The excess amount of oxygen in the TiO_x layer may react with Co and Pt to form oxides (as characterized by XPS) and result in the drop of coercivity. Thus the growth of the fct CoPt phase can be enhanced by optimizing the oxygen ratio during fabrication of the TiO_x layer and post annealing, which may find useful applications for future CoPt-based magnetic recording.

Original language	English (US)
Pages (from-to)	S354-S359
Journal	Surface and Coatings Technology
Volume	228
Issue number	SUPPL.1
DOIs	https://doi.org/10.1016/j.surfcoat.2012.05.103
State	Published - Aug 15 2013
Externally published	Yes

All Science Journal Classification (ASJC) codes

General Chemistry
Condensed Matter Physics
Surfaces and Interfaces
Surfaces, Coatings and Films
Materials Chemistry

Keywords

CoPt
Ion-beam assisted deposition
Magnetic thin films

Access to Document

10.1016/j.surfcoat.2012.05.103

Cite this

@article{90d565d9ada34b2c916bac8c28a55ee5,

title = "Oxygen-stoichiometry-dependent microstructural and magnetic properties of CoPt thin films capped with ion-beam-assisted deposited TiOx layers",

abstract = "The magnetic properties of CoPt with different percentages of oxygen in the TiOx capping layer were investigated through annealing processes. Results have shown that after annealing, the structural phase transformation from fcc to fct CoPt occurred and was confirmed by the enhanced coercivities. In addition, the isolated CoPt grains separated by grain boundary TiOx in the annealed CoPt/TiOx (30% O2/Ar) thin films exhibited the largest coercivity. The excess amount of oxygen in the TiOx layer may react with Co and Pt to form oxides (as characterized by XPS) and result in the drop of coercivity. Thus the growth of the fct CoPt phase can be enhanced by optimizing the oxygen ratio during fabrication of the TiOx layer and post annealing, which may find useful applications for future CoPt-based magnetic recording.",

keywords = "CoPt, Ion-beam assisted deposition, Magnetic thin films",

author = "Guijun Li and Leung, {Chi Wah} and Chin Shueh and Wu, {Yi Jing} and Lin, {Ko Wei} and Sun, {An Cheng} and Hsu, {Jen Hwa} and Lai, {Pui To} and Pong, {Philip W.T.}",

year = "2013",

month = aug,

day = "15",

doi = "10.1016/j.surfcoat.2012.05.103",

language = "English (US)",

volume = "228",

pages = "S354--S359",

journal = "Surface and Coatings Technology",

issn = "0257-8972",

publisher = "Elsevier B.V.",

number = "SUPPL.1",

}

TY - JOUR

T1 - Oxygen-stoichiometry-dependent microstructural and magnetic properties of CoPt thin films capped with ion-beam-assisted deposited TiOx layers

AU - Li, Guijun

AU - Leung, Chi Wah

AU - Shueh, Chin

AU - Wu, Yi Jing

AU - Lin, Ko Wei

AU - Sun, An Cheng

AU - Hsu, Jen Hwa

AU - Lai, Pui To

AU - Pong, Philip W.T.

PY - 2013/8/15

Y1 - 2013/8/15

N2 - The magnetic properties of CoPt with different percentages of oxygen in the TiOx capping layer were investigated through annealing processes. Results have shown that after annealing, the structural phase transformation from fcc to fct CoPt occurred and was confirmed by the enhanced coercivities. In addition, the isolated CoPt grains separated by grain boundary TiOx in the annealed CoPt/TiOx (30% O2/Ar) thin films exhibited the largest coercivity. The excess amount of oxygen in the TiOx layer may react with Co and Pt to form oxides (as characterized by XPS) and result in the drop of coercivity. Thus the growth of the fct CoPt phase can be enhanced by optimizing the oxygen ratio during fabrication of the TiOx layer and post annealing, which may find useful applications for future CoPt-based magnetic recording.

AB - The magnetic properties of CoPt with different percentages of oxygen in the TiOx capping layer were investigated through annealing processes. Results have shown that after annealing, the structural phase transformation from fcc to fct CoPt occurred and was confirmed by the enhanced coercivities. In addition, the isolated CoPt grains separated by grain boundary TiOx in the annealed CoPt/TiOx (30% O2/Ar) thin films exhibited the largest coercivity. The excess amount of oxygen in the TiOx layer may react with Co and Pt to form oxides (as characterized by XPS) and result in the drop of coercivity. Thus the growth of the fct CoPt phase can be enhanced by optimizing the oxygen ratio during fabrication of the TiOx layer and post annealing, which may find useful applications for future CoPt-based magnetic recording.

KW - CoPt

KW - Ion-beam assisted deposition

KW - Magnetic thin films

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U2 - 10.1016/j.surfcoat.2012.05.103

DO - 10.1016/j.surfcoat.2012.05.103

M3 - Article

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SN - 0257-8972

VL - 228

SP - S354-S359

JO - Surface and Coatings Technology

JF - Surface and Coatings Technology

IS - SUPPL.1

ER -