Diagnosis of Surface Stability of 80K-Phase BiSrCaCuO Single Crystals with and without Li Doping

The surface structure of 80 K-phase BiSrCaCuO single crystals with and without Li doping has been studied using low-energy electron diffraction (LEED) at elevated temperatures. Although the superconducting critical temperature rises slightly with Li doping, the cleaved surface becomes amorphous in vacuum at temperature ∼100 degrees lower than that of the undoped sample (600°C).