Electronic states of the pristine and alkali-metal-intercalated monolayer graphite/Ni(111) systems

The electronic states of the pristine and alkali-metal-intercalated monolayer graphite (MG)/Ni(111) systems are investigated by using angle-resolved ultraviolet photoelectron spectroscopy and x-ray-photoelectron spectroscopy (XPS). The electronic structure of the MG is modified largely by hybridization of the π orbitals of the graphite layer with the d orbitals of the substrate. The deposition of alkali-metal atoms onto the graphite overlayer at room temperature results in the penetration of the adsorbates into the interface between the MG and the Ni(111) surface. This intercalation causes the change in the band structure of the system because of the dilation of the MG-Ni interlayer distance. The intercalation of the alkali-metal atoms also shows the broadening of the XPS peak of the C 1s core level of the MG.