Element and phase identification via fine structure analysis in EELS: application to MOCVD-Y1Ba2Cu3O7-delta thin films

International audienceElectron energy loss spectroscopy (EELS) in the transmission electron microscope (TEM) is a very useful tool for identifying small secondary phases, for example, in YBCO off-stoichiometric thin films. Among these phases are the CuO and Y2BaCuO5 submicrometric precipitates and the Y2O3 nanometric inclusions. Beyond the classical elementary analysis based on the quantitative exploitation of core-level signals, we propose a new method of identification based on the interpretation of the fine structures in the EELS spectrum such as the near-edge structures (ELNES) at the O–K edge and the low-loss signatures. We also propose a method for determining the parameter δ in Y1Ba2Cu3O7−δ from the volume plasmon energy, which is more direct and has the same accuracy as the method proposed by Browning, based on modelling of the O–K edge