MgGa2O4 spinel barrier for magnetic tunnel junctions: coherent tunneling and low barrier height
- Resource Type
- Authors
- Tadakatsu Ohkubo; Mohamed Belmoubarik; Tadaomi Daibou; Yuuzo Kamiguchi; Junichi Ito; Hiroaki Yoda; P.-H. Cheng; Hiroaki Sukegawa; Seiji Mitani; Naoharu Shimomura; Kazuhiro Hono; Yushi Kato
- Source
- Subject
- 010302 applied physics
Condensed Matter - Materials Science
Materials science
Physics and Astronomy (miscellaneous)
Condensed matter physics
Spinel
Oxide
chemistry.chemical_element
Materials Science (cond-mat.mtrl-sci)
FOS: Physical sciences
02 engineering and technology
engineering.material
Sputter deposition
021001 nanoscience & nanotechnology
Epitaxy
01 natural sciences
Tetragonal crystal system
chemistry.chemical_compound
Tunnel magnetoresistance
chemistry
0103 physical sciences
engineering
Gallium
0210 nano-technology
Quantum tunnelling
- Language
Epitaxial Fe/magnesium gallium spinel oxide (MgGa2O4)/Fe(001) magnetic tunnel junctions (MTJs) were fabricated by magnetron sputtering. Tunnel magnetoresistance (TMR) ratio up to 121% at room temperature (196% at 4 K) was observed, suggesting a TMR enhancement by the coherent tunneling effect in the MgGa2O4 barrier. The MgGa2O4 layer had a spinel structure and it showed good lattice matching with the Fe layers owing to slight tetragonal lattice distortion of MgGa2O4. Barrier thickness dependence of the tunneling resistance and current-voltage characteristics revealed that the barrier height of the MgGa2O4 barrier is much lower than that in an MgAl2O4 barrier. This study demonstrates the potential of Ga-based spinel oxides for MTJ barriers having a large TMR ratio at a low resistance area product.
Comment: 4 figures, 1 table