XPS STUDIES OF Bi 2 Sr 2 CaCu 2-x Li x O y CERAMICS SERFACES

The XPS(X-ray photoelectron spectroscope) measurements of the 80K phase Bi-Sr-Ca-Cu-Li-O ceramics were carried out on surfaces obtained by polishing in ultrahigh vacuum. The results show that the chemical bond natures of Bi and Sr almost did not change, but the binding energies of Ca, Cu and O shifted apparently toward higher energy when Li doped in the Bi-Sr-Ca-Cu-O system. The XPS spectrum of O Is has only singe peak (528.8eV) from clean surfaces polished in vacuum and consists of the O H (531eV) and O L (528.8eV) components from conventionally polished surfaces.