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Enhancement of Magnetoresistance in Granular CrO2/Polystyrene Composites |
| CHEN Ya-Jie1,2;ZHANG Xiao-Yu1;LI Zhen-Ya1,3 |
| 1Department of Physics, Suzhou University, Suzhou 215006
2Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093
3CCAST (World Laboratory), PO Box 8730, Beijing 100080 |
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| Cite this article: |
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CHEN Ya-Jie, ZHANG Xiao-Yu, LI Zhen-Ya 2003 Chin. Phys. Lett. 20 1578-1581 |
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Abstract We present a study of magnetotransport in CrO2/polystyrene (PS) composites over a range of polystyrene concentration (0-30 wt.%). In the experiment, an obvious enhancement in magnetoresistance (MR) is observed at 77 K and at room temperature as the half-metallic CrO2 particles are encapsulated with a thin layer of insulating polystyrene. The enhanced MR can be interpreted in terms of spin-dependent intergranular tunneling with 4-nm-thick PS barrier. Moreover, it is found that the novel PS barrier contributes to room-temperature MR more significantly than that at 77 K. Temperature dependence of resistance is good agreement with ～ T-1/4 in the temperature range from 77 to 298 K.
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| Keywords:
72.25.-b
72.80.Tm
75.47.-m
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Published: 01 September 2003
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| PACS: |
72.25.-b
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(Spin polarized transport)
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72.80.Tm
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(Composite materials)
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75.47.-m
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(Magnetotransport phenomena; materials for magnetotransport)
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