Deep Co penetration and spin-polarization of C60 molecules at hybridized Co-C60 interfaces

Abstract

We used near-edge x-ray absorption fine structure spectroscopy to identify the interplays at organic semiconductor-ferromagnet interfaces. When monitoring the L-edge intensity of 0.36 nm Co depositing on C60 films of various thicknesses, we detected weaker Co signal from structures with larger C 60 thicknesses. Having determined that the electron mean escape depth in C60 is 4.9 nm, further model analysis indicates that the decline of spectral intensity is due to deep penetration of Co clusters. Finally, C K-edge spectra reveal clear evidences of orbital hybridization between Co and C60 as well as a visible dichroic effect at 125 K. © 2014 AIP Publishing LLC.