STM observation of metal-nonmetal granular thin films
- 1 January 1999
- journal article
- Published by The Magnetics Society of Japan in Journal of the Magnetics Society of Japan
- Vol. 23 (1_2) , 82-84
- https://doi.org/10.3379/jmsjmag.23.82
Abstract
We have observed scanning tunneling microscopy (STM) topographic images for structural characterization and measured current-voltage (I-V) spectra (scanning tunneling spectroscopy: STS) for the investigation of local transport properties of Co-Al-O granular thin films exhibiting tunnel-type giant magnetoresistance (GMR). STM topographic images indicated round-shaped bright regions and dark channels, which are associated with Co granules and Al-oxide, respectively. From the I-V characteristics the electronic charging effect, i. e., the effect of Coulomb blockade, was confirmed. In addition, the tunneling current varied stepwise as a function of the voltage, suggesting the appearance of a Coulomb staircase.Keywords
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