Transmission Electron Microscopy Analysis of Nanorods in BaSnO3-Doped ErBa2Cu3O7-δ Films

Abstract

Microstructures of BaSnO3-doped ErBa2Cu3O7-δ films were studied by transmission electron microscopy. BaSnO3-doped ErBa2Cu3O7-δ films were grown by a pulsed laser deposition method. In the cross-sectional transmission electron microscopy observation, the presence of nanorods with 10 nm average diameter was confirmed from bright-field images, and these nanorods in turn contained tin (Sn), as confirmed from the energy-dispersive X-ray spectroscopy spectra. The crystal structure of the nanorod was determined to be cubic perovskite from its selected area electron diffraction pattern. Using the selected area electron diffraction patterns, the lattice constant of the nanorods in the ErBa2Cu3O7-δ film was measured to be 0.414 nm. This was in good agreement with the lattice constant of BaSnO3, 0.412 nm. Furthermore, parallel Moiré fringes were observed in the bright-field images, and the relationships between the lattice planes and Moiré fringes were investigated. It was thus confirmed that BaSnO3 was dispersed in the ErBa2Cu3O7-δ as nanorods.