Laboratory preparation of LSM and LSF sputtering targets using PTFE rings for deposition of SOFC thin film electrodes

Abstract

The manufacturing of sputtering targets diverges from the conventional methods in ceramic processing, primarily because the quantities produced are frequently limited. The application of hot-press in this scenario significantly simplifies the sputter target fabrication process, allowing precise control over both target density and dimensions during pressing. However, without a hot press, the fabrication necessitates substantial preliminary efforts, which may be challenging to justify due to the restricted production volume. This study utilizes polytetrafluoroethylene (PTFE) rings as compaction dies filled with powders. Subsequently, the die is deformed between parallel platens, effectively compacting the powders. The method relies on the characteristic that the pressing results in minimal change in the internal diameter of the ring. This approach was exemplified through the creation of 2-inch (La0.5Sr0.5) MnO3-δ (LSM) and (La0.8Sr0.2) FeO3-δ (LSF) targets, where the deformable die was sized based on preliminary experiments involving smaller-diameter PTFE rings. The outcome of this fabrication process successfully produced sputter targets with high density, well within the tolerances of the sputter gun. Further tests involved using the prepared targets for the successful deposition of thin film LSM-LSF composite cathodes for SOFC applications.