Magneto-optical and spin-transfer switching properties of current-perpendicular-to plane spin valves with perpendicular magnetic anisotropy

Ken Ichi Aoshima, Nobuhiko Funabashi, Kenji Machida, Yasuyoshi Miyamoto, Norikazu Kawamura, Kiyoshi Kuga, Naoki Shimidzu, Takashi Kimura, Yoshichika Otani, Fumio Sato

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

We evaluated the magneto-optical properties of spin-valve (SV) stacks with perpendicular magnets comprised of a Gd-Fe (4-30 nm) free layer and a Tb-Fe-Co/CoFe pinned layer, and the spin-transfer switching properties of current-perpendicular-to-plane (CPP) SVs with the perpendicular magnets. The Gd-Fe free layer had polar Kerr rotation θk of 0.12° at a thickness of 10 nm. The θk reduced with a decrease in GdFe thickness and the sign of θk switched from positive to negative at a Gd-Fe thickness of 6 nm or thinner. Coercivity (Hc) was maximum and saturation magnetization (Ms) was minimum at a thickness of 8 nm. These phenomena may be explained by an inhomogeneous Gd-Fe composition. The CPP spin valves with the Gd-Fe (10 nm) free layer had a magneto-resistance (MR) of 0.038%. The free layer of a CPP SV device was switched by a pulsed current, which exhibited intrinsic switching current densities of Jc0-P-AP = -3.3 × 107 A/cm2 and Jc0-AP-P = 4.3 × 107 A/cm2 with a thermal stability of 75, which is above the required value of 40. Perpendicular magnets are very useful for obtaining large magneto-optical signals from nano-magnets driven by spin-transfer switching.

Original languageEnglish
Pages (from-to)2491-2495
Number of pages5
JournalIEEE Transactions on Magnetics
Volume44
Issue number11 PART 2
DOIs
Publication statusPublished - Nov 1 2008

Fingerprint

Magnetic anisotropy
Magnets
Magnetoresistance
Saturation magnetization
Coercive force
Thermodynamic stability
Current density
Optical properties
Chemical analysis

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Electrical and Electronic Engineering

Cite this

Magneto-optical and spin-transfer switching properties of current-perpendicular-to plane spin valves with perpendicular magnetic anisotropy. / Aoshima, Ken Ichi; Funabashi, Nobuhiko; Machida, Kenji; Miyamoto, Yasuyoshi; Kawamura, Norikazu; Kuga, Kiyoshi; Shimidzu, Naoki; Kimura, Takashi; Otani, Yoshichika; Sato, Fumio.

In: IEEE Transactions on Magnetics, Vol. 44, No. 11 PART 2, 01.11.2008, p. 2491-2495.

Research output: Contribution to journalArticle

Aoshima, KI, Funabashi, N, Machida, K, Miyamoto, Y, Kawamura, N, Kuga, K, Shimidzu, N, Kimura, T, Otani, Y & Sato, F 2008, 'Magneto-optical and spin-transfer switching properties of current-perpendicular-to plane spin valves with perpendicular magnetic anisotropy', IEEE Transactions on Magnetics, vol. 44, no. 11 PART 2, pp. 2491-2495. https://doi.org/10.1109/TMAG.2008.2002615
Aoshima, Ken Ichi ; Funabashi, Nobuhiko ; Machida, Kenji ; Miyamoto, Yasuyoshi ; Kawamura, Norikazu ; Kuga, Kiyoshi ; Shimidzu, Naoki ; Kimura, Takashi ; Otani, Yoshichika ; Sato, Fumio. / Magneto-optical and spin-transfer switching properties of current-perpendicular-to plane spin valves with perpendicular magnetic anisotropy. In: IEEE Transactions on Magnetics. 2008 ; Vol. 44, No. 11 PART 2. pp. 2491-2495.
@article{39dd2586bd1d4ca9a1c91137fc25a5b2,
title = "Magneto-optical and spin-transfer switching properties of current-perpendicular-to plane spin valves with perpendicular magnetic anisotropy",
abstract = "We evaluated the magneto-optical properties of spin-valve (SV) stacks with perpendicular magnets comprised of a Gd-Fe (4-30 nm) free layer and a Tb-Fe-Co/CoFe pinned layer, and the spin-transfer switching properties of current-perpendicular-to-plane (CPP) SVs with the perpendicular magnets. The Gd-Fe free layer had polar Kerr rotation θk of 0.12° at a thickness of 10 nm. The θk reduced with a decrease in GdFe thickness and the sign of θk switched from positive to negative at a Gd-Fe thickness of 6 nm or thinner. Coercivity (Hc) was maximum and saturation magnetization (Ms) was minimum at a thickness of 8 nm. These phenomena may be explained by an inhomogeneous Gd-Fe composition. The CPP spin valves with the Gd-Fe (10 nm) free layer had a magneto-resistance (MR) of 0.038{\%}. The free layer of a CPP SV device was switched by a pulsed current, which exhibited intrinsic switching current densities of Jc0-P-AP = -3.3 × 107 A/cm2 and Jc0-AP-P = 4.3 × 107 A/cm2 with a thermal stability of 75, which is above the required value of 40. Perpendicular magnets are very useful for obtaining large magneto-optical signals from nano-magnets driven by spin-transfer switching.",
author = "Aoshima, {Ken Ichi} and Nobuhiko Funabashi and Kenji Machida and Yasuyoshi Miyamoto and Norikazu Kawamura and Kiyoshi Kuga and Naoki Shimidzu and Takashi Kimura and Yoshichika Otani and Fumio Sato",
year = "2008",
month = "11",
day = "1",
doi = "10.1109/TMAG.2008.2002615",
language = "English",
volume = "44",
pages = "2491--2495",
journal = "IEEE Transactions on Magnetics",
issn = "0018-9464",
publisher = "Institute of Electrical and Electronics Engineers Inc.",
number = "11 PART 2",

}

TY - JOUR

T1 - Magneto-optical and spin-transfer switching properties of current-perpendicular-to plane spin valves with perpendicular magnetic anisotropy

AU - Aoshima, Ken Ichi

AU - Funabashi, Nobuhiko

AU - Machida, Kenji

AU - Miyamoto, Yasuyoshi

AU - Kawamura, Norikazu

AU - Kuga, Kiyoshi

AU - Shimidzu, Naoki

AU - Kimura, Takashi

AU - Otani, Yoshichika

AU - Sato, Fumio

PY - 2008/11/1

Y1 - 2008/11/1

N2 - We evaluated the magneto-optical properties of spin-valve (SV) stacks with perpendicular magnets comprised of a Gd-Fe (4-30 nm) free layer and a Tb-Fe-Co/CoFe pinned layer, and the spin-transfer switching properties of current-perpendicular-to-plane (CPP) SVs with the perpendicular magnets. The Gd-Fe free layer had polar Kerr rotation θk of 0.12° at a thickness of 10 nm. The θk reduced with a decrease in GdFe thickness and the sign of θk switched from positive to negative at a Gd-Fe thickness of 6 nm or thinner. Coercivity (Hc) was maximum and saturation magnetization (Ms) was minimum at a thickness of 8 nm. These phenomena may be explained by an inhomogeneous Gd-Fe composition. The CPP spin valves with the Gd-Fe (10 nm) free layer had a magneto-resistance (MR) of 0.038%. The free layer of a CPP SV device was switched by a pulsed current, which exhibited intrinsic switching current densities of Jc0-P-AP = -3.3 × 107 A/cm2 and Jc0-AP-P = 4.3 × 107 A/cm2 with a thermal stability of 75, which is above the required value of 40. Perpendicular magnets are very useful for obtaining large magneto-optical signals from nano-magnets driven by spin-transfer switching.

AB - We evaluated the magneto-optical properties of spin-valve (SV) stacks with perpendicular magnets comprised of a Gd-Fe (4-30 nm) free layer and a Tb-Fe-Co/CoFe pinned layer, and the spin-transfer switching properties of current-perpendicular-to-plane (CPP) SVs with the perpendicular magnets. The Gd-Fe free layer had polar Kerr rotation θk of 0.12° at a thickness of 10 nm. The θk reduced with a decrease in GdFe thickness and the sign of θk switched from positive to negative at a Gd-Fe thickness of 6 nm or thinner. Coercivity (Hc) was maximum and saturation magnetization (Ms) was minimum at a thickness of 8 nm. These phenomena may be explained by an inhomogeneous Gd-Fe composition. The CPP spin valves with the Gd-Fe (10 nm) free layer had a magneto-resistance (MR) of 0.038%. The free layer of a CPP SV device was switched by a pulsed current, which exhibited intrinsic switching current densities of Jc0-P-AP = -3.3 × 107 A/cm2 and Jc0-AP-P = 4.3 × 107 A/cm2 with a thermal stability of 75, which is above the required value of 40. Perpendicular magnets are very useful for obtaining large magneto-optical signals from nano-magnets driven by spin-transfer switching.

UR - http://www.scopus.com/inward/record.url?scp=77955222394&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=77955222394&partnerID=8YFLogxK

U2 - 10.1109/TMAG.2008.2002615

DO - 10.1109/TMAG.2008.2002615

M3 - Article

AN - SCOPUS:77955222394

VL - 44

SP - 2491

EP - 2495

JO - IEEE Transactions on Magnetics

JF - IEEE Transactions on Magnetics

SN - 0018-9464

IS - 11 PART 2

ER -