Large tunnel magnetoresistance at room temperature with a Co2FeAl full-Heusler alloy electrode
- 1. CREST, Japan Science and Technology Agency, 4-1-8 Honcho Kawaguchi, Saitama 332-0012 (Japan)
- 2. Department of Materials Science, Graduate School of Engineering, Tohoku University, Aoba-yama 6-6-02, Sendai 980-8579 (Japan)
Description
Magnetic tunnel junctions (MTJs) with a Co2FeAl Heusler alloy electrode are fabricated by the deposition of the film using an ultrahigh vacuum sputtering system followed by photolithography and Ar ion etching. A tunnel magnetoresistance (TMR) of 47% at room temperature (RT) are obtained in a stack of Co2FeAl/Al-Ox/Co75Fe25 magnetic tunnel junction (MTJ) fabricated on a thermally oxidized Si substrate despite the A2 type atomic site disorder for Co2FeAl. There is no increase of TMR in MTJs with the B2 type Co2FeAl, which is prepared by the deposition on a heated substrate. X-ray photoelectron spectroscopy (XPS) depth profiles in Co2FeAl single layer films reveal that Al atoms in Co2FeAl are oxidized preferentially at the surfaces. On the other hand, at the interfaces in Co2FeAl/Al-Ox/Co75Fe25 MTJs, the ferromagnetic layers are hardly oxidized during plasma oxidation for a formation of Al oxide barriers
Additional details
Identifiers
- DOI
- 10.1063/1.1944893;
Publishing Information
- Journal Title
- Applied Physics Letters
- Journal Volume
- 86
- Journal Issue
- 23
- Journal Page Range
- p. 232503-232503.3
- ISSN
- 0003-6951
- CODEN
- APPLAB
INIS
- Country of Publication
- United States
- Country of Input or Organization
- International Atomic Energy Agency (IAEA)
- INIS RN
- 37017569
- Subject category
- S36: MATERIALS SCIENCE;
- Descriptors DEI
- ALUMINIUM OXIDES; ARGON IONS; COBALT ALLOYS; DEPOSITION; ELECTRODES; ETCHING; FERROMAGNETIC MATERIALS; HEUSLER ALLOYS; INTERFACES; IRON ALLOYS; LAYERS; MAGNETORESISTANCE; OXIDATION; SPUTTERING; SUBSTRATES; SUPERCONDUCTING JUNCTIONS; TEMPERATURE RANGE 0273-0400 K; THIN FILMS; TUNNEL EFFECT; X-RAY PHOTOELECTRON SPECTROSCOPY
- Descriptors DEC
- ALLOYS; ALUMINIUM ALLOYS; ALUMINIUM COMPOUNDS; CHALCOGENIDES; CHARGED PARTICLES; CHEMICAL REACTIONS; COPPER ALLOYS; COPPER BASE ALLOYS; CORROSION RESISTANT ALLOYS; ELECTRIC CONDUCTIVITY; ELECTRICAL PROPERTIES; ELECTRON SPECTROSCOPY; FILMS; IONS; MAGNETIC MATERIALS; MANGANESE ALLOYS; MATERIALS; OXIDES; OXYGEN COMPOUNDS; PHOTOELECTRON SPECTROSCOPY; PHYSICAL PROPERTIES; SPECTROSCOPY; SURFACE FINISHING; TEMPERATURE RANGE; TRANSITION ELEMENT ALLOYS
Optional Information
- Notes
- (c) 2005 American Institute of Physics