Supplementary Materials for Antisite defects in La0.7Sr0.3MnO3 and La0.7Sr0.3FeO3 Meng Gu1,2, Zhiguo Wang3, Michael D Biegalski4, Hans M Christen4, Yayoi Takamura1 and Nigel D Browning1, 5, Department of Chemical Engineering and Materials Science, University of California-Davis, Davis, California, 95616 Present address: Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland WA 99354 Department of Applied Physics, University of Electronic Science and Technology of China, Chengdu, 610054, P.R China Center for Nanophase Materials Science, Oak Ridge National Laboratory, Oak Ridge, Tennessee, 37831; 5Department of Molecular and Cellular Biology, University of CaliforniaDavis, Davis, CA, 95616, 95616; Present address: Fundamental & Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland WA 99354 This supplementary material section provides details regarding to Z-contrast imaging, electron energy loss (EEL) spectroscopy, and the density functional theory (DFT) calculations in this study The KrF laser (248 nm) was operated at 10 Hz with an energy density of ~ 1.5 J/cm The substrate was heated to 7700C and the chamber pressure was held at 200 mTorr O The growth of these superlattices was monitored in-situ using reflection high energy electron diffraction After the deposition, the film was cooled to room temperature in 200 Torr of O The samples for STEM were polished to electron transparency using the wedge polishing method using a Multiprep machine from Allied High Tech Products, Inc A Fischione ion milling system was used for low-voltage (2kV) Ar cleaning for about 30 minutes to remove the mechanically damaged surface layer The images shown in Fig 1(a,b) and Fig were obtained using a probe aberrationcorrected JEM2100F STEM operating at 200 kV with a convergence angle of 18 mrad and collection semi-angle of around 110-300 mrad at UC Davis The images in Fig S2 and EEL spectra were acquired using the TEAM 0.5 microscope operating at 80 kV to avoid beam damage at the National Center for Electron Microscopy at Lawrence Berkeley National Laboratory The Z-contrast images acquired using TEAM 0.5 had a convergence angle of 29 mrad and collection semi-angle of 90-390 mrad and the EELS inner collection angle was 100 mrad The first-principles calculations are performed based on DFT using projector augmented wave potentials (PAW)1 The exchange correlation is described in the generalized gradient approximations (GGA)2 using the PW91 functional as implemented in the VASP code PAW potentials with valence configurations of 5s25p65d16s2, 3p63d64s2, 3d64s1, and 2s22p4 are used to describe the La, Fe, Mn and O atoms, respectively Defect calculations are simulated with 240atom (4a0×4a0×3a0; a0 is the lattice constant of a cubic LaMnO (LMO) or LaFeO3 (LFO) perovskite) supercell A plane-wave expansion of the wave functions up to a kinetic-energy cutoff of 400 eV has been employed and the Brillouin zone was sampled by a Monkhorst-Pack kpoint mesh of 2×2×2 The defect formation energy of a native defect is simply the reaction energy to create the defect from ideal matter The formation energy is not a constant but depends on the growth or annealing conditions4 The formation energy of a defect in charge state is defined as4, E f [ X q ] = Etot [ X q ] − Etot [pefect] − ∑ ni µ i + q( EF + EVBM ) i (1) q where Etot [ X ] is the total energy of a supercell containing a relaxed defect (vacancy or antisite) with charge state q, Etot [pefect ] is the total energy of the supercell without defects ni indicates the number of atoms of type i atoms that have been added to (ni>0) or removed from (ni