Boron composition dependence of spin-transfer switching in magnetic tunnel junctions with CoFeB free layers

Daisuke Watanabe; Mikihiko Oogane; Shigemi Mizukami; Yasuo Ando; Terunobu Miyazaki

doi:10.1143/JJAP.48.013001

Boron composition dependence of spin-transfer switching in magnetic tunnel junctions with CoFeB free layers

Daisuke Watanabe, Mikihiko Oogane, Shigemi Mizukami, Yasuo Ando, Terunobu Miyazaki

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

6 Citations (Scopus)

Abstract

We investigated tunnel magnetoresistance (TMR) and magnetization switching due to spin-transfer torque in CoFeB/MgO/CoFeB junctions having three different free layer compositions, (Co₅₀Fe₅₀)_100-xB _x (x = 20, 25, 30), and measured their magnetic properties, including magnetization (M_s) and Gilbert damping constant (α), which are theoretically predicted to contribute to the critical current density (J _c0) for spin-transfer switching. We found that the J_c0 in the magnetic tunnel junctions (MTJs) with x = 30 became smaller than that in the MTJs with x = 20 despite having a lower TMR ratio and a larger α. We showed that the J_c0 for each composition tends to follow the theoretical relationship for the magnetic factor of the free layer.

Original language	English
Article number	013001
Journal	Japanese journal of applied physics
Volume	48
Issue number	1
DOIs	https://doi.org/10.1143/JJAP.48.013001
Publication status	Published - 2009 Jan 20

ASJC Scopus subject areas

Engineering(all)
Physics and Astronomy(all)

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abstract = "We investigated tunnel magnetoresistance (TMR) and magnetization switching due to spin-transfer torque in CoFeB/MgO/CoFeB junctions having three different free layer compositions, (Co50Fe50)100-xB x (x = 20, 25, 30), and measured their magnetic properties, including magnetization (Ms) and Gilbert damping constant (α), which are theoretically predicted to contribute to the critical current density (J c0) for spin-transfer switching. We found that the Jc0 in the magnetic tunnel junctions (MTJs) with x = 30 became smaller than that in the MTJs with x = 20 despite having a lower TMR ratio and a larger α. We showed that the Jc0 for each composition tends to follow the theoretical relationship for the magnetic factor of the free layer.",

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T1 - Boron composition dependence of spin-transfer switching in magnetic tunnel junctions with CoFeB free layers

AU - Watanabe, Daisuke

AU - Oogane, Mikihiko

AU - Mizukami, Shigemi

AU - Ando, Yasuo

AU - Miyazaki, Terunobu

PY - 2009/1/20

Y1 - 2009/1/20

N2 - We investigated tunnel magnetoresistance (TMR) and magnetization switching due to spin-transfer torque in CoFeB/MgO/CoFeB junctions having three different free layer compositions, (Co50Fe50)100-xB x (x = 20, 25, 30), and measured their magnetic properties, including magnetization (Ms) and Gilbert damping constant (α), which are theoretically predicted to contribute to the critical current density (J c0) for spin-transfer switching. We found that the Jc0 in the magnetic tunnel junctions (MTJs) with x = 30 became smaller than that in the MTJs with x = 20 despite having a lower TMR ratio and a larger α. We showed that the Jc0 for each composition tends to follow the theoretical relationship for the magnetic factor of the free layer.

AB - We investigated tunnel magnetoresistance (TMR) and magnetization switching due to spin-transfer torque in CoFeB/MgO/CoFeB junctions having three different free layer compositions, (Co50Fe50)100-xB x (x = 20, 25, 30), and measured their magnetic properties, including magnetization (Ms) and Gilbert damping constant (α), which are theoretically predicted to contribute to the critical current density (J c0) for spin-transfer switching. We found that the Jc0 in the magnetic tunnel junctions (MTJs) with x = 30 became smaller than that in the MTJs with x = 20 despite having a lower TMR ratio and a larger α. We showed that the Jc0 for each composition tends to follow the theoretical relationship for the magnetic factor of the free layer.

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Boron composition dependence of spin-transfer switching in magnetic tunnel junctions with CoFeB free layers

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