Direct observation of half-metallic energy gap in Co{sub 2}MnSi by tunneling conductance spectroscopy

Journal Article · Mon Jul 31 04:00:00 EDT 2006 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.2335583· OSTI ID:20860652

Sakuraba, Y; Miyakoshi, T; Oogane, M; Ando, Y; Sakuma, A; Miyazaki, T; Kubota, H ^[1]

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1. Department of Applied Physics, Graduate School of Engineering, Tohoku University, Aoba-yama 6-6-05, Aramaki, Aoba-ku, Sendai 980-8579 (Japan)

Magnetic tunnel junctions with a Co{sub 2}MnSi/Al-O/CoFe structure are prepared by magnetron sputtering and investigated with respect to the energy gap near the Fermi energy level. The plasma oxidation time for the Al-O barrier is found to affect the condition of the Co{sub 2}MnSi/Al-O interface. The optimized sample (50 s oxidation time) exhibits a magnetoresistance ratio of 159% and tunneling spin polarization of 0.89 at 2 K. The bias voltage dependence of tunneling conductance (dI/dV-V) reveals a clear half-metallic energy gap at 350-400 meV for Co{sub 2}MnSi, with an energy separation of just 10 meV between the Fermi energy and the bottom edge of conduction band.

• OSTI ID: 20860652
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 5 Vol. 89; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM OXIDES
COBALT ALLOYS
DEPOSITION
ELECTRIC POTENTIAL
ENERGY GAP
FERMI LEVEL
FERROMAGNETIC MATERIALS
IRON ALLOYS
MAGNETORESISTANCE
MANGANESE ALLOYS
OXIDATION
SILICON ALLOYS
SPECTROSCOPY
SPIN ORIENTATION
SPUTTERING
SUPERCONDUCTING JUNCTIONS
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0000-0013 K
TUNNEL EFFECT