Examining the relationship between the atomic scale structure, composition and bonding at grain boundaries and the bulk electronic properties of perovskite oxides

摘要

Here we report the analysis of grain boundaries in several related perovskite oxide systems using atomic resolution scanning transmission electron microscopy (STEM). By performing simultaneous Z-contrast imaging and electron energy loss spectroscopy in the STEM, the structure, composition and bonding at the grain boundaries can be characterized on the atomic scale. The features of the boundaries that are observed in the model system, SrTiO_3, are also found in the high-T_c superconductors YBa_2Cu_3O_7 and (Bi,Pb)_2Sr_2Ca_2Cu_3O_(10). The implications for the electronic properties of these materials are discussed.