Interface magnetism of Co{sub 2}FeGe Heusler alloy layers and magnetoresistance of Co{sub 2}FeGe/MgO/Fe magnetic tunnel junctions

Journal Article · Tue Oct 28 00:00:00 EDT 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4898761· OSTI ID:22308160

Maezaki, D.; Ishii, T.; Okubo, A.; Mibu, K. ^[1]; Hiramatsu, R.; Ono, T. ^[2]

---

1. Department of Engineering Physics, Electronics and Mechanics, Nagoya Institute of Technology, Nagoya, Aichi 466-8555 (Japan)
2. Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011 (Japan)

The interface magnetism between Co{sub 2}FeGe Heusler alloy layers and MgO layers was investigated using {sup 57}Fe Mössbauer spectroscopy. Interface-sensitive samples, where the {sup 57}Fe isotope was used only for the interfacial atomic layer of the Co{sub 2}FeGe layer on the MgO layer, were prepared using atomically controlled alternate deposition. The {sup 57}Fe Mössbauer spectra of the interface-sensitive samples at room temperature were found similar to those of the bulk-sensitive Co{sub 2}FeGe films in which the {sup 57}Fe isotope was distributed throughout the films. On the other hand, the tunnel magnetoresistance effect of magnetic tunnel junctions with Co{sub 2}FeGe layers as the ferromagnetic electrodes showed strong reduction at room temperature. These results indicate that the strong temperature dependence of the tunneling magnetoresistance of magnetic tunnel junctions using Heusler alloy electrodes cannot be attributed simply to the reduction of the magnetization at the interfaces between the Heusler alloy and insulator layers.

• OSTI ID: 22308160
• Journal Information: Journal of Applied Physics, Vol. 116, Issue 16; Other Information: (c) 2014 AIP Publishing LLC; 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
COBALT COMPOUNDS
DEPOSITION
FILMS
GERMANIUM COMPOUNDS
HEUSLER ALLOYS
INTERFACES
IRON
IRON 57
IRON COMPOUNDS
LAYERS
MAGNESIUM OXIDES
MAGNETISM
MAGNETIZATION
MAGNETORESISTANCE
MOESSBAUER EFFECT
SPECTRA
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0273-0400 K
TUNNEL DIODES
TUNNEL EFFECT