CHANNELING STUDIES OF HF IMPLANTED INTO TIO2 SINGLE-CRYSTALS - LATTICE DISORDER AND LATTICE LOCATION

The RBS-channeling spectrometry was used to analyse the lattice disorder produced by implantation of 300 keV Hf at a dose of 5.10(14) Hf+/cm2 into TiO2 (rutile) single crystals at 77 K and during isochronal annealing up to 1500 K. After implantation at 77 K the implanted region was channeling-amorphous. The recovery of the disorder occurred in a first annealing stage between 500 K and 800 K. Here the disorder peak area decreased by about 20%. A second annealing stage occurred at temperatures between 1000-1300 K where primarily the width decreased indicating an epitaxial solid phase regrowth. The recovery was completed at 1273 K. At 1473 K a minimum yield value of 2% was reached, similar to that of the virgin crystal. Hafnium starts to diffuse towards the surface forming a surface peak at about 800 K. At 1100 K a triple peak is formed. Indiffusion of Hf occurred at 1270 K and above revealing a substitutional fraction of about 100%. Implantation of 8.10(14) Hf+/cm2 at 1070 K resulted a substitutional component of 80%.