ABSTRACTAu-ions were implanted at RT conventionally and through a mask into TiO₂- and SrTiO₃-single crystals with doses in the range from 1×10¹⁵Au⁺/cm² to 1×10¹⁷Au⁺/cm², and dose rates of ∼10¹¹ions/sec and ∼3×10¹³ions/sec, at an energy of 260keV; some samples subsequently were annealed at temperatures up to 1100K. The Au-atoms precipitated to nanocrystals during implantation with an average particle size of 1.5nm. HRTEM investigations revealed that the Au-nanocrystals, embedded in amorphous TiO₂-regions, have a broad size distribution varying from large sizes in the near surface region to smaller sizes at larger depths. In the annealing process a coarsening and a reorientation of the Au-nanocrystals is observed. At 1000K the particle size of the textured Au-implant was evaluated to be ∼6nm. Implantation with a high dose rate performed through a metal mask with holes of 120μm diameter and without annealing resulted in an almost equidistant arrangement of the Au-nanocrystals with a narrow size distribution of 2–6nm in TiO₂ and 3–5nm in SrTiO₃ in the near surface region. Au-ion implantation through an e-beam resist mask (50nm × 50nm holes), with doses ranging from 1×10¹⁵Au⁺/cm² to 4×10¹⁵Au⁺/cm² at the low dose rate and annealed at 1000K, lead to a periodic structure of the Au-nanocrystals. The nanocrystal size, evaluated from TEM analysis, in the as-implanted state was ∼5nm and after annealing at 1000K sizes of several nanometers to several tens of nanometers were observed.