Chemical and structural characterization of La0.5Sr0.5MnO3 thin films prepared by pulsed-laser deposition

La0.5Sr0.5MnO3 thin films were deposited onto sapphire substrates by means of the pulsed-laser deposition technique. These films were characterized by several techniques including x-ray diffraction, Rutherford backscattering spectrometry, energy-dispersive x-ray, atomic-force microscopy, scanning el ectron microscopy, and x-ray photoelectron spectroscopy (XPS). The cation r atios are the same in the deposited films as in the target. However, stront ium segregation occurs at the film surface with an enrichment in this, elem ent compared to Mn and La, as shown by XPS. In addition, a clear correlatio n between the three different contributions which compose the O(1s) XPS sig nal and the Sr, La, and Mn surface concentrations has been established. Ann ealing the films at a sufficiently high-temperature produces the same cryst al structure as in the target. (C) 2001 American Vacuum Society.