Current-perpendicular-to-plane giant magnetoresistance using Co{sub 2}Fe(Ga{sub 1-x}Ge{sub x}) Heusler alloy

Journal Article · Mon Jan 28 00:00:00 EST 2013 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4788672· OSTI ID:22102242

Goripati, H. S. ^[1]; Furubayashi, T.; Takahashi, Y. K. ^[2]; Hono, K. ^[2]

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1. Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba 305-0047 (Japan)
2. Magnetic Materials Unit, National Institute for Materials Science, Tsukuba 305-0047 (Japan)

We investigated the current-perpendicular-to-plane giant magnetoresistance (CPP-GMR) of pseudo spin valves (PSVs) using ferromagnetic (FM) Heusler alloy Co{sub 2}Fe(Ga{sub 1-x}Ge{sub x}) (x = 0, 0.5, and 1) layers and an Ag spacer layer. The FM layer with x = 0.5 gave rise to the highest MR output, {Delta}RA = 8.7 m{Omega}{center_dot}{mu}m{sup 2}, at room temperature with 10 nm thick Heusler alloy layers. The MR output increased with increasing annealing temperature, T{sub a}, with a maximum at T{sub a} = 500 Degree-Sign C. Transmission electron microscopy showed no visible changes in the layered structure; however, energy dispersive x-ray analysis indicated a considerable diffusion of Ga and Ge into the other layers by annealing at T{sub a} = 550 Degree-Sign C. The {Delta}RA dependence on the thickness of the FM layers indicated that both high bulk and interface spin asymmetries contribute to the high MR output.

• OSTI ID: 22102242
• Journal Information: Journal of Applied Physics, Vol. 113, Issue 4; Other Information: (c) 2013 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
36 MATERIALS SCIENCE
ANNEALING
ASYMMETRY
COBALT COMPOUNDS
DIFFUSION
FERROMAGNETIC MATERIALS
GALLIUM COMPOUNDS
GERMANIUM COMPOUNDS
HEUSLER ALLOYS
INTERFACES
IRON COMPOUNDS
LAYERS
MAGNETORESISTANCE
SPIN
TEMPERATURE RANGE 0273-0400 K
THICKNESS
THIN FILMS
TRANSMISSION ELECTRON MICROSCOPY
X RADIATION