Tunable interfacial magnetic-optical properties of Co doped amorphous carbon film induced by charge transfer after acid treatment

Changes of the magnetic-optical properties at the interface of a Co doped amorphous carbon film before and after treatments with diluted sulfuric acid are performed by a magnetic circular dichroism spectroscopy. A considerable enhancement (or decrease) signal is observed in samples with different microstructures. X-ray absorption data of these samples reveal that Co, C and molecular dopants compete with each other after sulfuric acid treatment during charge transfer. Moreover, from above observations, the sizeable magneto-optical effects are contributed by the hybridization effect at the Co/C interface.