Investigation of structure and magnetoresistance in Co/ZnO films

Journal Article · Mon Nov 15 00:00:00 EST 2010 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3511752· OSTI ID:21537937

Zhiyong, Quan; Xiaohong, Xu; Xiaoli, Li ^[1]; Feng, Q; Gehring, G A ^[2]

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1. School of Chemistry and Materials Science, Shanxi Normal University, Linfen 041004 (China)
2. Department of Physics and Astronomy, University of Sheffield, Hicks Building, Sheffield S3 7RH (United Kingdom)

Co/ZnO films were deposited on glass substrates by magnetron sputtering at room temperature. The structure of the as-deposited films is studied by means of x-ray diffraction, x-ray photoelectron spectroscopy, and the zero-field-cooled and field-cooled magnetization curves. It is shown that the as-deposited samples consist of a mixture of regions of metallic Co and semiconducting ZnO. Large negative magnetoresistance of 26% and 11.9% are observed in the as-deposited Co/ZnO film with Co concentration of 50.7 at. % at 10 K and room temperature, respectively. Structural analysis, the temperature dependence of the conductivity and magnetoresistance reveal that the magnetoresistance is induced by spin-dependent tunneling between regions of conducting magnetic Co through the ZnO semiconducting barriers. The enhanced magnetoresistance in the low temperature regime may be related to the existence of higher-order tunneling processes between large Co regions mediated by small Co particles.

• OSTI ID: 21537937
• Journal Information: Journal of Applied Physics, Vol. 108, Issue 10; Other Information: DOI: 10.1063/1.3511752; (c) 2010 American Institute of Physics; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
COBALT
DEPOSITION
GLASS
LAYERS
MAGNETIZATION
MAGNETORESISTANCE
MAGNETRONS
MIXTURES
SEMICONDUCTOR MATERIALS
SPIN
SPUTTERING
SUBSTRATES
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0273-0400 K
THIN FILMS
TUNNEL EFFECT
X-RAY DIFFRACTION
X-RAY PHOTOELECTRON SPECTROSCOPY
ZINC OXIDES
ANGULAR MOMENTUM
CHALCOGENIDES
COHERENT SCATTERING
DIFFRACTION
DISPERSIONS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRON SPECTROSCOPY
ELECTRON TUBES
ELECTRONIC EQUIPMENT
ELEMENTS
EQUIPMENT
FILMS
MATERIALS
METALS
MICROWAVE EQUIPMENT
MICROWAVE TUBES
OXIDES
OXYGEN COMPOUNDS
PARTICLE PROPERTIES
PHOTOELECTRON SPECTROSCOPY
PHYSICAL PROPERTIES
SCATTERING
SPECTROSCOPY
TEMPERATURE RANGE
TRANSITION ELEMENTS
ZINC COMPOUNDS