Formation of Au$_4$Zr nanocrystals in yttria stabilized zirconia in the course of implantation of gold ions

High-resolution transmission microscopy and optical absorption spectroscopy have been used to examine how metallic nanocrystals (NCs) are formed in the course of implantation of Au ions into thin films of yttria stabilized zirconia (YSZ) and subsequent thermal annealing. It was found that, under certain implantation conditions, Au$_4$Zr NCs are formed in addition to Au NCs in the YSZ matrix. The conditions in which Au$_4$Zr NCs are formed in the course of implantation and decompose under the subsequent annealing were determined.