Atomic-scale identification of novel planar defect phases in heteroepitaxial YBa2Cu3O7−δ thin films

We have discovered two novel types of planar defects that appear in heteroepitaxial YBa2Cu3O7−δ (YBCO123) thin films, grown by pulsed-laser deposition (PLD) either with or without a La2/3Ca1/3MnO3 (LCMO) overlayer, using the combination of high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) imaging and electron energy loss spectroscopy (EELS) mapping for unambiguous identification. These planar lattice defects …