Band structure modification of AI oxide by Ti-alloying and magnetoresistance behavior of magnetic tunnel junctions with Ti-alloyed Al oxide barrier

Jin Oh Song; Seong Rae Lee; Hyun Joon Shin

doi:10.1063/1.1949726

Band structure modification of AI oxide by Ti-alloying and magnetoresistance behavior of magnetic tunnel junctions with Ti-alloyed Al oxide barrier

Jin Oh Song, Seong Rae Lee, Hyun Joon Shin

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

8 Citations (Scopus)

Abstract

We investigated the composition dependence of the band structure of Ti-alloyed Al oxide (TiAlO_x), tunneling magnetoresistance (TMR) behavior of the magnetic tunnel junctions (MTJs) with TiAlO_x barrier, and the microstructural evolution of Ti-Al alloy films. X-ray absorption spectroscopy indicated that TiAlO_x. had localized d states in the band gap below the conduction band. As the Ti concentration increased, the resistance × area value and effective barrier height of the MTJs were reduced owing to the band-gap reduction of TiAlO_x caused by the formation of extra bands, mainly composed of Ti 3d orbitals, within the band gap. The TMR ratio increased up to 49% at 5.33 at. % Ti. Ti alloying enhanced the barrier/electrode interface uniformity and reduced microstructural defects. These structural improvements enhanced not only the TMR effect but also the thermal stability of the MTJs.

Original language	English
Article number	252501
Pages (from-to)	1-3
Number of pages	3
Journal	Applied Physics Letters
Volume	86
Issue number	25
DOIs	https://doi.org/10.1063/1.1949726
Publication status	Published - 2005
Externally published	Yes

ASJC Scopus subject areas

Physics and Astronomy (miscellaneous)

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@article{3acbde0352af4fbd8fe11595ba469e77,

title = "Band structure modification of AI oxide by Ti-alloying and magnetoresistance behavior of magnetic tunnel junctions with Ti-alloyed Al oxide barrier",

abstract = "We investigated the composition dependence of the band structure of Ti-alloyed Al oxide (TiAlOx), tunneling magnetoresistance (TMR) behavior of the magnetic tunnel junctions (MTJs) with TiAlOx barrier, and the microstructural evolution of Ti-Al alloy films. X-ray absorption spectroscopy indicated that TiAlOx. had localized d states in the band gap below the conduction band. As the Ti concentration increased, the resistance × area value and effective barrier height of the MTJs were reduced owing to the band-gap reduction of TiAlOx caused by the formation of extra bands, mainly composed of Ti 3d orbitals, within the band gap. The TMR ratio increased up to 49% at 5.33 at. % Ti. Ti alloying enhanced the barrier/electrode interface uniformity and reduced microstructural defects. These structural improvements enhanced not only the TMR effect but also the thermal stability of the MTJs.",

author = "Song, {Jin Oh} and Lee, {Seong Rae} and Shin, {Hyun Joon}",

note = "Funding Information: This work was supported by the Korea Ministry of Science and Technology under contract National Research Laboratory program, the Korea Research Foundation Grant (KRF-2004-005-C00068), and the Basic Research Program of the Korea Science and Engineering Foundation Grant (R-01-2005-000-11188-0). ",

year = "2005",

doi = "10.1063/1.1949726",

language = "English",

volume = "86",

pages = "1--3",

journal = "Applied Physics Letters",

issn = "0003-6951",

publisher = "American Institute of Physics Publising LLC",

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T1 - Band structure modification of AI oxide by Ti-alloying and magnetoresistance behavior of magnetic tunnel junctions with Ti-alloyed Al oxide barrier

AU - Song, Jin Oh

AU - Lee, Seong Rae

AU - Shin, Hyun Joon

N1 - Funding Information: This work was supported by the Korea Ministry of Science and Technology under contract National Research Laboratory program, the Korea Research Foundation Grant (KRF-2004-005-C00068), and the Basic Research Program of the Korea Science and Engineering Foundation Grant (R-01-2005-000-11188-0).

PY - 2005

Y1 - 2005

N2 - We investigated the composition dependence of the band structure of Ti-alloyed Al oxide (TiAlOx), tunneling magnetoresistance (TMR) behavior of the magnetic tunnel junctions (MTJs) with TiAlOx barrier, and the microstructural evolution of Ti-Al alloy films. X-ray absorption spectroscopy indicated that TiAlOx. had localized d states in the band gap below the conduction band. As the Ti concentration increased, the resistance × area value and effective barrier height of the MTJs were reduced owing to the band-gap reduction of TiAlOx caused by the formation of extra bands, mainly composed of Ti 3d orbitals, within the band gap. The TMR ratio increased up to 49% at 5.33 at. % Ti. Ti alloying enhanced the barrier/electrode interface uniformity and reduced microstructural defects. These structural improvements enhanced not only the TMR effect but also the thermal stability of the MTJs.

AB - We investigated the composition dependence of the band structure of Ti-alloyed Al oxide (TiAlOx), tunneling magnetoresistance (TMR) behavior of the magnetic tunnel junctions (MTJs) with TiAlOx barrier, and the microstructural evolution of Ti-Al alloy films. X-ray absorption spectroscopy indicated that TiAlOx. had localized d states in the band gap below the conduction band. As the Ti concentration increased, the resistance × area value and effective barrier height of the MTJs were reduced owing to the band-gap reduction of TiAlOx caused by the formation of extra bands, mainly composed of Ti 3d orbitals, within the band gap. The TMR ratio increased up to 49% at 5.33 at. % Ti. Ti alloying enhanced the barrier/electrode interface uniformity and reduced microstructural defects. These structural improvements enhanced not only the TMR effect but also the thermal stability of the MTJs.

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DO - 10.1063/1.1949726

M3 - Article

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SN - 0003-6951

VL - 86

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EP - 3

JO - Applied Physics Letters

JF - Applied Physics Letters

IS - 25

M1 - 252501

ER -

Band structure modification of AI oxide by Ti-alloying and magnetoresistance behavior of magnetic tunnel junctions with Ti-alloyed Al oxide barrier

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