Effect of oxygen stoichiometry on microstructural and magnetic properties of FePt/TaOx bilayer fabricated by ion-beam-bombardment deposition

G. J. Li; C. W. Leung; Y. C. Chen; J. H. Hsu; A. C. Sun; K. W. Lin; Philip W.T. Pong

doi:10.1109/TMAG.2013.2247383

Effect of oxygen stoichiometry on microstructural and magnetic properties of FePt/TaO_x bilayer fabricated by ion-beam-bombardment deposition

G. J. Li, C. W. Leung, Y. C. Chen, J. H. Hsu, A. C. Sun, K. W. Lin, Philip W.T. Pong

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

4 Scopus citations

Abstract

The effect of TaO_x capping layer on microstructures and magnetic properties of FePt thin films via annealing was studied. The structural ordering of FePt from face-centered cubic to face-centered tetragonal phases depends strongly on the oxygen contents in the capping TaO_x layer. The role of the TaO_x layer is used to separate the FePt grains, as revealed by TEM. The annealed FePt/TaO_x (15%O₂/Ar) exhibited the largest out-of-plane coercivity (H_c 4.2 kOe) amongst all samples, compared to that (∼2.4 kOe) in the reference FePt layer. At low oxygen content in FePt/TaO_x bilayers, the Ta atoms may act as defects to obstruct the FePt ordering whereas at high oxygen contents, the excess oxygen atoms diffuse into the FePt layer and react with Fe to form iron oxides which give rise to the low coercivities, as characterized by the XPS depth profile and binding energy analysis.

Original language	English (US)
Article number	6559126
Pages (from-to)	3310-3313
Number of pages	4
Journal	IEEE Transactions on Magnetics
Volume	49
Issue number	7
DOIs	https://doi.org/10.1109/TMAG.2013.2247383
State	Published - 2013
Externally published	Yes

All Science Journal Classification (ASJC) codes

Electronic, Optical and Magnetic Materials
Electrical and Electronic Engineering

Keywords

FePt
ion-beam bombardment
magnetic properties

Access to Document

10.1109/TMAG.2013.2247383

Cite this

@article{0e9fda3386b349f1a43f2b03177e727b,

title = "Effect of oxygen stoichiometry on microstructural and magnetic properties of FePt/TaOx bilayer fabricated by ion-beam-bombardment deposition",

abstract = "The effect of TaOx capping layer on microstructures and magnetic properties of FePt thin films via annealing was studied. The structural ordering of FePt from face-centered cubic to face-centered tetragonal phases depends strongly on the oxygen contents in the capping TaOx layer. The role of the TaOx layer is used to separate the FePt grains, as revealed by TEM. The annealed FePt/TaOx (15%O2/Ar) exhibited the largest out-of-plane coercivity (Hc 4.2 kOe) amongst all samples, compared to that (∼2.4 kOe) in the reference FePt layer. At low oxygen content in FePt/TaOx bilayers, the Ta atoms may act as defects to obstruct the FePt ordering whereas at high oxygen contents, the excess oxygen atoms diffuse into the FePt layer and react with Fe to form iron oxides which give rise to the low coercivities, as characterized by the XPS depth profile and binding energy analysis.",

keywords = "FePt, ion-beam bombardment, magnetic properties",

author = "Li, {G. J.} and Leung, {C. W.} and Chen, {Y. C.} and Hsu, {J. H.} and Sun, {A. C.} and Lin, {K. W.} and Pong, {Philip W.T.}",

year = "2013",

doi = "10.1109/TMAG.2013.2247383",

language = "English (US)",

volume = "49",

pages = "3310--3313",

journal = "IEEE Transactions on Magnetics",

issn = "0018-9464",

publisher = "Institute of Electrical and Electronics Engineers Inc.",

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}

TY - JOUR

T1 - Effect of oxygen stoichiometry on microstructural and magnetic properties of FePt/TaOx bilayer fabricated by ion-beam-bombardment deposition

AU - Li, G. J.

AU - Leung, C. W.

AU - Chen, Y. C.

AU - Hsu, J. H.

AU - Sun, A. C.

AU - Lin, K. W.

AU - Pong, Philip W.T.

PY - 2013

Y1 - 2013

N2 - The effect of TaOx capping layer on microstructures and magnetic properties of FePt thin films via annealing was studied. The structural ordering of FePt from face-centered cubic to face-centered tetragonal phases depends strongly on the oxygen contents in the capping TaOx layer. The role of the TaOx layer is used to separate the FePt grains, as revealed by TEM. The annealed FePt/TaOx (15%O2/Ar) exhibited the largest out-of-plane coercivity (Hc 4.2 kOe) amongst all samples, compared to that (∼2.4 kOe) in the reference FePt layer. At low oxygen content in FePt/TaOx bilayers, the Ta atoms may act as defects to obstruct the FePt ordering whereas at high oxygen contents, the excess oxygen atoms diffuse into the FePt layer and react with Fe to form iron oxides which give rise to the low coercivities, as characterized by the XPS depth profile and binding energy analysis.

AB - The effect of TaOx capping layer on microstructures and magnetic properties of FePt thin films via annealing was studied. The structural ordering of FePt from face-centered cubic to face-centered tetragonal phases depends strongly on the oxygen contents in the capping TaOx layer. The role of the TaOx layer is used to separate the FePt grains, as revealed by TEM. The annealed FePt/TaOx (15%O2/Ar) exhibited the largest out-of-plane coercivity (Hc 4.2 kOe) amongst all samples, compared to that (∼2.4 kOe) in the reference FePt layer. At low oxygen content in FePt/TaOx bilayers, the Ta atoms may act as defects to obstruct the FePt ordering whereas at high oxygen contents, the excess oxygen atoms diffuse into the FePt layer and react with Fe to form iron oxides which give rise to the low coercivities, as characterized by the XPS depth profile and binding energy analysis.

KW - FePt

KW - ion-beam bombardment

KW - magnetic properties

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