Direct measurement of barrier asymmetry in AlO{sub x}/ZrO{sub y} magnetic tunnel junctions using off-axis electron holography

Journal Article · Sun Apr 01 00:00:00 EDT 2007 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PHYSREVB.75.134420· OSTI ID:20957790

Yuzi, Liu ^[1]; Wang, W G; Moriyama, T; Xiao, John Q ^[2]; Zhang, Z ^[3]

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1. Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, P.O. Box 603, Beijing 100080 (China)
2. Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716 (United States)
3. Beijing University of Technology, 100 Pingle Yuan, Chao Yang District, Beijing 100022 (China)

Off-axis electron holography was used to investigate the barrier profile of the Py/AlO{sub x}/ZrO{sub y}/Py magnetic tunnel junctions with different ZrO{sub y} thicknesses. The tunneling magnetoresistance (TMR) has a strong dependence on bias voltage and the bias voltage for maximum TMR is shifted from zero. This shift increases with ZrO{sub y} barrier thickness due to the increasing barrier asymmetry in the junctions. The evolution of barrier asymmetry was directly observed by the phase change of the off-axis electron holography, which unambiguously shows the barrier profile changes from triangular to trapezoidal shape as increasing of ZrO{sub y} thickness.

• OSTI ID: 20957790
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Vol. 75, Issue 13; Other Information: DOI: 10.1103/PhysRevB.75.134420; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALUMINIUM COMPOUNDS
ASYMMETRY
AUGMENTATION
ELECTRIC POTENTIAL
ELECTRONS
HOLOGRAPHY
MAGNETORESISTANCE
PHASE TRANSFORMATIONS
SUPERCONDUCTING JUNCTIONS
THICKNESS
TUNNEL EFFECT
ZIRCONIUM COMPOUNDS