LEED-AES observations of 7 K- and 80 K-phase Bi-Sr-Ca-Cu-O single crystals

LEED and AES observations were made on the clean surfaces of 7 K- and 80 K-phase Bi-Sr-Ca-Cu-O single crystals. It is clear that the surface structure of the 7 K-phase crystal is the same as that of the 80 K-phase crystal. The clean surfaces of the specimens are very stable without any adsorption of CO2 and O2 gases. However, in light of the fact that the intensity of carbon becomes greater in the AES spectrum after baking a chamber, the active carbon compounds are thought to be adsorbed on the clean surfaces of the 7 K- and 80 K-phase single crystals. (author)