Site-resolved oxygen K-edge ELNES of the layered double perovskite La2CuSnO6

Electron energy-loss spectroscopy (EELS) combined with scanning transmission electron microscopy (STEM) allows for the investigation of the local electronic structure with atomic column resolution, owing to the development of spherical aberration correctors. In the present research, we report B-site-resolved oxygen K-edge energy-loss near-edge structure (ELNES) measured from a double perovskite La2CuSnO6 (LCSO) using STEM-EELS. There are two kinds of BO6(B=Sn and Cu) octahedrons, arranged in layers in the LCSO crystal. The observed site-resolved oxygen K-edge ELNES showed different features reflecting local chemical bonding around the Sn and Cu ions. In particular, it is demonstrated that the local electronic structure in the distorted CuO6 octahedron caused by the Jahn-Teller effect can be detected by site-resolved ELNES.