Tailoring of La_xSr_1‐xCo_yFe_1‐yO_3‐δ Nanostructure by Pulsed Laser Deposition

Abstract

Pulsed Laser Deposition (PLD) was used to prepare thin fi lms with the nominal composition La 0.58 Sr 0.4 Co 0.2 Fe 0.8 O 3− δ (LSCF). The thin fi lm microstructure was investigated as a function of PLD deposition parameters such as: substrate temperature, ambient gas pressure, target-to-substrate distance, laser fl uence and frequency. It was found that the ambient gas pressure and the substrate temperature are the key PLD process parameters determining the thin fi lm micro-and nanostructure. A map of the LSCF fi lm nanostructures is presented as a function of substrate temperature (25-700 ° C) and oxygen background pressure (0.013-0.4 mbar), with fi lm structures ranging from fully dense to highly porous. Fully crystalline, dense, and crack-free LSCF fi lms with a thickness of 300 nm were obtained at an oxygen pressure lower than 0.13 mbar at a temperature of 600 ° C. The obtained knowledge on the structure allows for tailoring of perovskite thin fi lm nanostructure, e.g., for solid oxide fuel cell cathodes. A simple geometrical model is proposed, allowing estimation of the catalytic active surface area of the prepared thin fi lms. It is shown that voids at columnar grain boundaries can result in an increase of the surface area by approximately 25 times, when compared to dense fl at fi lms.

The Superior Properties of La0.6Ba0.4CoO3-δThin Film Electrodes for Oxygen Exchange in Comparison to La0.6Sr0.4CoO3-δ

“…Both thin films show a very similar dense packing of columnar shaped grains, which is expected for the PLD growth conditions applied. 33,34 No voids or pinholes were observed in the cross-sections. For both materials crack formation could not be avoided, as seen in the top views in Fig.…”

In Situ TEM Analysis of a Symmetric Solid Oxide Cell in Oxygen and Vacuum – Cation Diffusion Observations

“…This is often observed when the deposition is made on a substrate with different crystallinity or chemical bounding (17). This columnar growth of LSC prepared by PLD has previously been described (18)(19)(20).…”

Porous La0.6Sr0.4CoO3−δ thin film cathodes for large area micro solid oxide fuel cell power generators

“…Indeed, some attempts have been already reported on the development of pure oxide-based electrodes for fabricating fully-ceramic µSOFC, based on state-of-the-art materials on bulk SOFC systems working as cathodes [19][20][21][22][23][24][25][26][27] or anodes [28]. However, only few results have been reported on µSOFC performance using ceramic electrodes [29][30][31][32].…”