Tunnel magnetoresistance in epitaxially grown magnetic tunnel junctions using Heusler alloy electrode and MgO barrier

Journal Article · Wed Jul 01 04:00:00 EDT 2009 · Journal of Physics D: Applied Physics

DOI:https://doi.org/10.1088/0022-3727/42/19/195004· OSTI ID:973689

Tsunegi, S; Sakuraba, Y; Oogane, M; Telling, N D; Shelford, L R; Arenholz, E; van der Laan, G; Hicken, R J; Takanashi, K; Ando, Y

Epitaxially grown magnetic tunnel junctions (MTJs) with a stacking structure of Co{sub 2}MnSi/MgO/CoFe were fabricated. Their tunnel magnetoresistance (TMR) effects were investigated. The TMR ratio and tunnelling conductance characteristics of MTJs were considerably different between those with an MgO barrier prepared using sputtering (SP-MTJ) and those prepared using EB evaporation (EB-MTJ). The EB-MTJ exhibited a very large TMR ratio of 217% at room temperature and 753% at 2 K. The bias voltage dependence of the tunnelling conductance in the parallel magnetic configuration for the EB-MTJ suggests that the observed large TMR ratio at RT results from the coherent tunnelling process through the crystalline MgO barrier. The tunnelling conductance in the anti-parallel magnetic configuration suggests that the large temperature dependence of the TMR ratio results from the inelastic spin-flip tunnelling process.

• Research Organization: Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, CA (US)
• Sponsoring Organization: Advanced Light Source Division
• DOE Contract Number: AC02-05CH11231
• OSTI ID: 973689
• Report Number(s): LBNL-2648E
• Journal Information: Journal of Physics D: Applied Physics, Journal Name: Journal of Physics D: Applied Physics Journal Issue: 19 Vol. 42
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CONFIGURATION
ELECTRODES
EVAPORATION
HEUSLER ALLOYS
MAGNETORESISTANCE
SPIN FLIP
SPUTTERING
TEMPERATURE DEPENDENCE