Profile-Imaging of Wavy Cleavage Surface of Bi2Sr2CaCu2Oy by High-Resolution Transmission Electron Microscopy

Abstract
Profile-imaging of the (001) cleavage surface of Bi2Sr2CaCu2O y is performed by means of high-resolution transmission electron microscopy. The surface BiO layer suffers from structural modulation, almost in the same manner as (BiO)2 layers in the bulk structure [Y. Matsui et al., Jpn. J. Appl. Phys. 27 (1988) L372]. Small vertical fluctuation of the surface height, with a periodicity of 2.6 nm along the b axis, is observed. This wavy feature of the surface BiO layer is almost consistent with the recent scanning tunneling microscope (STM) study of Bi2Sr2CaCu2O y [M. D. Kirk et al., Science 242 (1988) 1673].