Giant magnetoresistance in Co-Al2O3 granular films prepared by self-organized growth
Co-Al2O3 granular films with a narrow distribution in cluster size of Co clusters embedded in Al2O3 matrix were prepared by sequential deposition based on self-organized growth. Resistivity dependence of giant magnetoresistance (GMR) was studied. The GMR takes a maximum of 5.2% at room temperature a...
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Veröffentlicht in: | Journal of magnetism and magnetic materials 2008-08, Vol.320 (15), p.2062-2067 |
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Hauptverfasser: | , , , , , , , , |
Format: | Artikel |
Sprache: | eng |
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Zusammenfassung: | Co-Al2O3 granular films with a narrow distribution in cluster size of Co clusters embedded in Al2O3 matrix were prepared by sequential deposition based on self-organized growth. Resistivity dependence of giant magnetoresistance (GMR) was studied. The GMR takes a maximum of 5.2% at room temperature and 9.4% at 13 K and 5700 Gs when the resistivity of the sample is 4X105-7X105 muOmega cm. The temperature dependence of resistivities and GMR were discussed especially. A temperature dependence of conductance rhoexp[T1/(T+T0)] was found, which indicates the dominant conduction mechanism is fluctuation-induced tunneling. A linear relationship of GMR versus T was observed, GMR=a-kT, in applied magnetic field 5700 Gs. The remarkable character of temperature dependence of GMR should be due to the special microstructure that the clusters are monodispersed in the films. |
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ISSN: | 0304-8853 |
DOI: | 10.1016/j.jmmm.2008.03.023 |