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摘要
The impact of cathodic bias on oxygen transport in La0.8Sr0.2MnO3 (LSM) thin films was investigated. Columnar-grown LSM thin films with different microstructures were deposited by pulsed laser deposition. O-18 tracer experiments were performed on thin film microelectrodes with an applied cathodic bias of -300 or -450 mV, and the microelectrodes were subsequently analyzed by time-of-flight secondary ion mass spectrometry. The O-18 concentration in the cathodically polarized LSM microelectrodes was strongly increased relative to that in the thermally annealed film (without bias). Most remarkable, however, was the appearance of a pronounced O-18 fraction maximum in the center of the films. This strongly depended on the applied bias and on the microstructure of the LSM thin layers. The unusual shape of the O-18 depth profiles was caused by a combination of Wagner-Hebb-type stoichiometry polarization of the LSM bulk, fast grain boundary transport and voltage-induced modification of the oxygen incorporation kinetics,
- 出版日期2015-10
