biostudies-literatureRiedl CÖsterreichische ForschungsförderungsgesellschaftAustrian Science Fund FWF142-153https://www.ebi.ac.uk/biostudies/studies/S-EPMC9768847biostudies-literatureUnknown25(1)La_0.6Sr_0.4FeO_3-<i>δ</i> (LSF) electrodes were grown on different electrolyte substrates by pulsed laser deposition (PLD) and their oxygen exchange reaction (OER) resistance was tracked in real-time by <i>in situ</i> PLD impedance spectroscopy (i-PLD) inside the PLD chamber. This enables measurements on pristine surfaces free from any contaminations and the direct observation of thickness dependent properties. As substrates, yttria-stabilized zirconia single crystals (YSZ) were used for polycrystalline LSF growth and La_0.95Sr_0.05Ga_0.95Mg_0.05O_3-<i>δ</i> (LSGM) single crystals or YSZ single crystals with a 5 nm buffer-layer of Gd_0.2Ce_0.8O_2-<i>δ</i> for epitaxial LSF film growth. While polycrystalline LSF electrodes show a constant OER resistance in a broad thickness range, epitaxially grown LSF electrodes exhibit a continuous and strong increase of the OER resistance with film thickness until ≈60 nm. In addition, the activation energy of the OER resistance increases by 0.23 eV compared to polycrystalline LSF. High resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) measurements reveal an increasing contraction of the out-of-plane lattice parameter in the epitaxial LSF electrodes over electrode thickness. Defect thermodynamic simulations suggest that the decrease of the LSF unit cell volume is accompanied by a lowering of the oxygen vacancy concentration, explaining both the resistive increase and the increased activation energy.Physical chemistry chemical physics : PCCP<i>In situ</i> electrochemical observation of anisotropic lattice contraction of La_0.6Sr_0.4FeO_3-<i>δ</i> electrodes during pulsed laser deposition.PMC9768847P31654 – N37P31165 – N37865864Limbeck ASiebenhofer MOpitz AKRiedl CRaznjevic SZhang ZFleig JBumberger AEKubicek Mfalse<i>In situ</i> electrochemical observation of anisotropic lattice contraction of La_0.6Sr_0.4FeO_3-<i>δ</i> electrodes during pulsed laser deposition.La_0.6Sr_0.4FeO_3-<i>δ</i> (LSF) electrodes were grown on different electrolyte substrates by pulsed laser deposition (PLD) and their oxygen exchange reaction (OER) resistance was tracked in real-time by <i>in situ</i> PLD impedance spectroscopy (i-PLD) inside the PLD chamber. This enables measurements on pristine surfaces free from any contaminations and the direct observation of thickness dependent properties. As substrates, yttria-stabilized zirconia single crystals (YSZ) were used for polycrystalline LSF growth and La_0.95Sr_0.05Ga_0.95Mg_0.05O_3-<i>δ</i> (LSGM) single crystals or YSZ single crystals with a 5 nm buffer-layer of Gd_0.2Ce_0.8O_2-<i>δ</i> for epitaxial LSF film growth. While polycrystalline LSF electrodes show a constant OER resistance in a broad thickness range, epitaxially grown LSF electrodes exhibit a continuous and strong increase of the OER resistance with film thickness until ≈60 nm. In addition, the activation energy of the OER resistance increases by 0.23 eV compared to polycrystalline LSF. High resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) measurements reveal an increasing contraction of the out-of-plane lattice parameter in the epitaxial LSF electrodes over electrode thickness. Defect thermodynamic simulations suggest that the decrease of the LSF unit cell volume is accompanied by a lowering of the oxygen vacancy concentration, explaining both the resistive increase and the increased activation energy.2022-01-01T00:00:00Z2022 Dec2025-04-04T10:59:01.919Z2025-04-04T10:59:01.919ZS-EPMC97688473647684110.1039/d2cp04977e