Reaction Joining of Aluminum-Doped Lanthanum Strontium Manganese Oxide to Yttria-Stabilized Tetragonal Zirconia for Gas Sensor Applications

Aluminum-doped lanthanum strontium manganese oxide (LSAM) has been investigated as an electrically conductive ceramic material. LSAM formulations with varying amounts of aluminum were synthesized using standard ceramic processing followed by pressure-less sintering in air. Electrical conductivity of LSAM was measured as a function of aluminum content and temperature. Optimum LSAM formulations were joined to yttria-stabilized tetragonal zirconia (YTZP) using a high-temperature deformation process. Electron microscopy, X-ray diffraction, and Raman spectroscopy were used to evaluate the joint interface. Joining was attributed to the formation of a reaction layer of strontium zirconate. Joining of LSAM to oxygen-ion conducting YTZP has implications in using this approach as interconnect for variety of high-temperature applications, including fuel cells and gas sensors.