TEM observation of ErBa2Cu3O7−δ films with BaZrO3 artificial pinning centers

Abstract

Microstructure of ErBa2Cu3O7−δ films with BaZrO3 as artificial pinning centers has been studied toward power application of a high temperature superconductor. ErBa2Cu3O7−δ films containing 1.5mass% BaZrO3 were grown by a pulsed laser deposition method. Microstructure of the ErBa2Cu3O7−δ film with BaZrO3 was investigated by transmission electron microscopy (TEM). In the cross-sectional TEM observation, the nano-rods grew up along near the c-axis of ErBa2Cu3O7−δ film were observed. Width of the nano-rods was about 10nm. We found twins with the averaged width of about 70nm. The moiré fringes were also observed. In the EDS mapping analysis, zirconium was not detected clearly from the present TEM specimen. Space of the moiré fringes is about 1.9nm. The lattice constant of a material in the ErBa2Cu3O7−δ film measured from the space of the moiré fringes is calculated to be 0.423nm which coincides with the lattice constant of BaZrO3 (0.419nm). Also, the lattice constant measured from the SADP is very close to the value of the BaZrO3. It is suggested that BaZrO3 disperses in ErBa2Cu3O7−δ film as the nano-rods.