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Chem. Mater., 2013, 25 (18), pp 3640–3647.
Roberto Moreno, Pablo García , James Zapata ,Jaume Roqueta , Julienne Chaigneau ,José Santiso.
ICN2, Institut Català de Nanociència i Nanotecnologia, Campus UAB, 08913 Bellaterra, Barcelona, Spain and
CSIC, Consejo Superior de Investigaciones Científicas, ICN2 Building, Campus UAB, 08193 Bellaterra, Barcelona, Spain.
Abstract
We have developed a new method to study the oxygen surface exchange kinetics in oxide materials in the form of epitaxial thin films by analyzing subtle cell parameter variations induced by changes in the oxygen stoichiometry of the material. The method consists of continuously analyzing the X-ray diffraction pattern of particular film reflections with a linear X-ray fast detector in a static position, while exposing the sample to sudden changes in thepO2 of the atmosphere at elevated temperatures. With this method, we have been able to follow cell parameter changes as small as 2.10–4 Å in time intervals as short as 10 s in La2NiO4+{Delta}epitaxial films and La2NiO4+{Delta}/LaNiO3−{Delta} bilayers. This method provides a simpler and contactless tool for dynamically analyzing oxygen surface exchange kinetics and diffusion in transition metal oxide compounds, and complements other currently used techniques such as Electric Conductivity Relaxation (ECR) and Isotopic Exchange depth profiling (IEDP). In addition, this method is a unique tool to address oxygen transport across solid–solid interfaces in thin film heterostructures.
Copyright © 2013 American Chemical Society.
