Magnetization, electrical conduction, and magnetoresistance (MR) of C60 -Co nanocomposites, where Co nanoparticles are dispersed in C60 molecules, have been investigated over a wide temperature range and Co volume fraction. The C60 -Co nanocomposites exhibit MR when the Co volume fraction is controlled in such a way that the conduction mechanism is dominated by tunneling of carriers between Co nanoparticles in the C60 matrix. The MR, which is attributed to spin-polarized tunneling through the C60 molecules, shows strong temperature dependence. Our results indicate that some paramagnetic components contribute to the observed MR. The material-dependent bias-voltage dependence of the MR ratio suggests that these paramagnetic components originate from the interface between organics and ferromagnets. The present study advances the fundamental understanding of spin-dependent transport in organic semiconductors.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 2007 Dec 19|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics