The electronic structures of the 8-hydroxyquinoline-aluminum (Alq_(3))/Al_(2)O_(3)/Co interfaces were studied by photoelectron spectroscopy. A strong interface dipole was observed, which leads to a reduction in the electron injection barrier. The x-ray photoelectron spectroscopy spectra further indicate that the Al_(2)O_(3) buffer layer prevents the chemical interaction between Alq_(3) molecules and Co atoms. X-ray magnetic circular dichroism results demonstrate that a Co layer deposited on an Al_(2)O_(3) buffered Alq_(3) layer shows better magnetic ordering in the interface region than directly deposited Co, which suggests a better performance of spin valves with such a buffer layer. This is consistent with the recent results from Dediu et al., Phys. Rev. B 78, 115203 (2008).
展开▼
