Strontium zirconate as silicon and aluminum scavenger in yttria stabilized zirconia

Here we report on strontium zirconate as a getter for silicon dioxide and aluminum oxide in yttria stabilized zirconia (YSZ) single crystals for cleaning purposes. YSZ single crystals were covered with strontium zirconate powder and heat treated at 1450 °C in water vapor. After treatment the YSZ single crystals showed homogeneously distributed ball-sectioned features (bumps) across the external surface of the crystal. The composition as quantified by energy-dispersive X-ray spectroscopy (EDS) showed a large enrichment of silicon and aluminum in the bumps. From cross-section analysis by transmission electron microscopy (TEM) the interface region between bump and YSZ single crystal bulk was examined. EDS showed a homogeneous distribution of silicon and aluminum through the cross section of a bump. The results suggest strontium zirconate as a good getter for silicon and aluminum from bulk materials at elevated temperatures and prove a route to remove trace bulk impurities in YSZ.

Research highlights
► Strontium zirconate can be used as getter for silicon dioxide and aluminium oxide.
► Ball-sectioned features was found on YSZ crystal after treatment.
► Features have a large content of silicon and aluminium.
► The features are conned to the external surface of the YSZ crystal.
► This opens up a new route for removing silicon and aluminium from YSZ crystals.