title: Incommensurate valence modulation in high-Tc cuprates
abstract: An incommensurate modulation has been observed in a Cu-rich La2CuO4.003 crystal. It is shown that the modulation results from a periodically distributed holes lying on the CuO2 planes, and that the hole modulation may be regarded to be a kind of valence modulation. It is shown that appreciable valence modulation contrast may be generated by the mechanisms of hole scattering alone when the period of the modulation is of the order of 2 nm.
authors.affiliation: Beijing Laboratory of Electron Microscopy, Institute of Physics and Center for Condensed Matter Physics, Chinese Academy of Sciences, Beijing, People's Republic of China. lmpeng@lmplab.blem.ac.cn
authors.initials: LM
authors.lastname: Peng
authors.initials: ZF
authors.lastname: Dong
authors.initials: XL
authors.lastname: Dong
authors.initials: BR
authors.lastname: Zhao
authors.initials: XF
authors.lastname: Duan
authors.initials: ZX
authors.lastname: Zhao