UltraSOFC Project
@ IREC
Insights into the enhancement of oxygen mass transport properties of strontium-doped lanthanum manganite interface-dominated thin films
BibTeX
Highlights
- • Interface-dominated La0.8Sr0,2MnO3 + δ dense thin films deposited by PLD
- • Several orders of magnitude of enhancement of oxygen mass transport properties
- • Unexpectedly small dependence of the oxygen mass transport properties with pO2
- • Model for the oxygen incorporation based on highly defective grain boundaries
Abstract
Strontium-doped lanthanum manganite thin films were deposited by pulsed laser deposition on yttria-stabilized zirconia single crystals for a comprehensive electrochemical characterization of the material acting as a cathode. A physically-meaningful electrical model was employed to fit the electrochemical impedance spectroscopy results in order to extract the main oxygen mass transport parameters as a function of the temperature and oxygen partial pressure. The oxygen diffusion and surface exchange coefficients extracted from the analysis showed several orders of magnitude of enhancement with respect to the bulk values reported in the literature and an unexpectedly low dependence with the oxygen partial pressure. Different observations were combined to propose a mechanism for the enhanced incorporation of oxygen in interface-dominated thin films mainly based on the high concentration of oxygen vacancies expected in the grain boundaries.
Keywords
LSM, Grain boundary, Oxygen mass transport, Thin film, MIEC