Investigations of chemical and electronic inhomogeneities in BaPb1-xBixO3 via highly spatially resolved electron energy loss spectroscopy

BaPb1-xBixO3 crystals, doped to various nominal x, were investigated in a scanning transmission electron microscope equipped with energy dispersive x-ray and electron energy loss spectroscopy facilities. Large compositional variations on the nm scale were found in single crystalline regions of any nominal x value. These were accompanied by changes in the core-loss and low-loss energy loss spectra. The low-loss energy loss spectra, furthermore, demonstrate the evolution of electronic structure with doping (i.e., transitions from semiconductor to semimetal) and fluctuations with variations in the local composition. (C) 2003 American Institute of Physics.