A new metallic, ordered perovskite thin film La6.4Sr1.6Cu8O22: pulsed laser deposition and microstructural characterization
Abstract
Pulsed laser deposition has been used to prepare thin films of a new perovskite, La6.4Sri1.6Cu8O22 with ordered oxygen vacancies. Energy dispersive scattering analysis confirms the stoichiometric deposition of the cations from the ceramic target, La6.4Sri1.6Cu8O20 Electron diffraction and high-resolution electron microscopic (HREM) studies show that the cell parameters are a=b= 2ap√2 and c=ap= 3.86 Å, but that the structure of the film differs from the target, bulk material, and suggests that the film is more oxygenated, according to the composition La6.4Sri1.6Cu8O22. The HREM images can be simulated from a model in which one-half of the oxygen vacancies in the bulk structure are filled. The film is well crystallized, [110] oriented with respect to the LaAlO3 substrate, and exhibits good metallic conductivity.