Effect of NiAl underlayer and spacer on magnetoresistance of current-perpendicular-to-plane spin valves using Co2Mn(Ga 0.5Sn0.5) Heusler alloy

N. Hase; T. M. Nakatani; S. Kasai; Y. K. Takahashi; T. Furubayashi; K. Hono

doi:10.1016/j.jmmm.2011.08.012

Effect of NiAl underlayer and spacer on magnetoresistance of current-perpendicular-to-plane spin valves using Co₂Mn(Ga _0.5Sn_0.5) Heusler alloy

N. Hase, T. M. Nakatani, S. Kasai, Y. K. Takahashi, T. Furubayashi, K. Hono^*

^*Corresponding author for this work

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

1 Citation (Scopus)

Abstract

We investigated the effect of a NiAl underlayer and spacer on magnetoresistive (MR) properties in current-perpendicular-to-plane spin valves (CPP-SVs) using Co₂Mn(Ga_0.5Sn_0.5) (CMGS) Heusler alloy ferromagnetic layers. The usage of a NiAl underlayer allowed a high temperature annealing for the L2₁ ordering of the bottom CMGS layer, giving rise to a MR ratio of 10.2% at room temperature. We found that the usage of a NiAl spacer layer also improved the tolerance of the multilayer structure against thermal delamination, which allowed annealing to induce the L2₁ structure in both the bottom and top CMGS layers. However, the short spin diffusion length of NiAl resulted in a lower MR ratio compared to that obtained using a Ag spacer. Transmission electron microscopy of the multilayer structure of CPP-SVs showed that the atomically flat layered structure was maintained after the annealing.

Original language	English
Pages (from-to)	440-444
Number of pages	5
Journal	Journal of Magnetism and Magnetic Materials
Volume	324
Issue number	4
DOIs	https://doi.org/10.1016/j.jmmm.2011.08.012
Publication status	Published - 2012 Feb
Externally published	Yes

Keywords

CPP-GMR
Giant magnetoresistance
Heusler alloy
Spin valve

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials
Condensed Matter Physics

Access to Document

10.1016/j.jmmm.2011.08.012

Cite this

@article{492cb5d07f904db3be5bcdad968edb38,

title = "Effect of NiAl underlayer and spacer on magnetoresistance of current-perpendicular-to-plane spin valves using Co2Mn(Ga 0.5Sn0.5) Heusler alloy",

abstract = "We investigated the effect of a NiAl underlayer and spacer on magnetoresistive (MR) properties in current-perpendicular-to-plane spin valves (CPP-SVs) using Co2Mn(Ga0.5Sn0.5) (CMGS) Heusler alloy ferromagnetic layers. The usage of a NiAl underlayer allowed a high temperature annealing for the L21 ordering of the bottom CMGS layer, giving rise to a MR ratio of 10.2% at room temperature. We found that the usage of a NiAl spacer layer also improved the tolerance of the multilayer structure against thermal delamination, which allowed annealing to induce the L21 structure in both the bottom and top CMGS layers. However, the short spin diffusion length of NiAl resulted in a lower MR ratio compared to that obtained using a Ag spacer. Transmission electron microscopy of the multilayer structure of CPP-SVs showed that the atomically flat layered structure was maintained after the annealing.",

keywords = "CPP-GMR, Giant magnetoresistance, Heusler alloy, Spin valve",

author = "N. Hase and Nakatani, {T. M.} and S. Kasai and Takahashi, {Y. K.} and T. Furubayashi and K. Hono",

note = "Funding Information: NH and TMN thank the National Institute for Materials Science for providing a NIMS junior research assistantship . This work was in part supported by the Grant-in-Aid for Scientific Research (A) (Grant no. 22246091 ), (B) 20360322 and PREST-JST .",

year = "2012",

month = feb,

doi = "10.1016/j.jmmm.2011.08.012",

language = "English",

volume = "324",

pages = "440--444",

journal = "Journal of Magnetism and Magnetic Materials",

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TY - JOUR

T1 - Effect of NiAl underlayer and spacer on magnetoresistance of current-perpendicular-to-plane spin valves using Co2Mn(Ga 0.5Sn0.5) Heusler alloy

AU - Hase, N.

AU - Nakatani, T. M.

AU - Kasai, S.

AU - Takahashi, Y. K.

AU - Furubayashi, T.

AU - Hono, K.

N1 - Funding Information: NH and TMN thank the National Institute for Materials Science for providing a NIMS junior research assistantship . This work was in part supported by the Grant-in-Aid for Scientific Research (A) (Grant no. 22246091 ), (B) 20360322 and PREST-JST .

PY - 2012/2

Y1 - 2012/2

N2 - We investigated the effect of a NiAl underlayer and spacer on magnetoresistive (MR) properties in current-perpendicular-to-plane spin valves (CPP-SVs) using Co2Mn(Ga0.5Sn0.5) (CMGS) Heusler alloy ferromagnetic layers. The usage of a NiAl underlayer allowed a high temperature annealing for the L21 ordering of the bottom CMGS layer, giving rise to a MR ratio of 10.2% at room temperature. We found that the usage of a NiAl spacer layer also improved the tolerance of the multilayer structure against thermal delamination, which allowed annealing to induce the L21 structure in both the bottom and top CMGS layers. However, the short spin diffusion length of NiAl resulted in a lower MR ratio compared to that obtained using a Ag spacer. Transmission electron microscopy of the multilayer structure of CPP-SVs showed that the atomically flat layered structure was maintained after the annealing.

AB - We investigated the effect of a NiAl underlayer and spacer on magnetoresistive (MR) properties in current-perpendicular-to-plane spin valves (CPP-SVs) using Co2Mn(Ga0.5Sn0.5) (CMGS) Heusler alloy ferromagnetic layers. The usage of a NiAl underlayer allowed a high temperature annealing for the L21 ordering of the bottom CMGS layer, giving rise to a MR ratio of 10.2% at room temperature. We found that the usage of a NiAl spacer layer also improved the tolerance of the multilayer structure against thermal delamination, which allowed annealing to induce the L21 structure in both the bottom and top CMGS layers. However, the short spin diffusion length of NiAl resulted in a lower MR ratio compared to that obtained using a Ag spacer. Transmission electron microscopy of the multilayer structure of CPP-SVs showed that the atomically flat layered structure was maintained after the annealing.

KW - CPP-GMR

KW - Giant magnetoresistance

KW - Heusler alloy

KW - Spin valve

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