Microstructure and synthesis mechanism of ScYSZ powders prepared by chemical co-precipitation with different dynamic microenvironment

Scandia and yttria co-stabilized zirconia (ScYSZ) ceramic powders were synthesized by various chemical co-precipitation methods. The structural difference and synthesis mechanism of the as-prepared ScYSZ powders were investigated in detail. Results show that all of the ScYSZ powders were synthesized with nanoscale and mainly exhibit tetragonal zirconia structure. ScYSZ precursors containing −[Zr–OH−Sc]− and −[Zr–OH–Y]− units can be formed through the chemical implantation of Sc 3+ and Y 3+ ions in the polymerization products of tetrameric [Zr 4 (OH) 8 ][H 2 O] 16 8+. During the sintering process, the ScYSZ precursors gradually transformed to corresponding oxide crystals through a series of dehydration, dehydroxylation and atomic prearrangement process. The structural and synthesis mechanism differences of various ScYSZ powders were mainly dominated by the dynamic microenvironment of reaction solutions, which can be attributed to the different polymerization modes of compound polymers as well as the uneven microdistribution of Sc 3+ and Y 3+ in ScYSZ precursors.