Amorphization kinetics in strontium titanate at 16 and 300 K under argon ion irradiation

The accumulation of irradiation-induced disorder in SrTiO₃ single crystals irradiated at 16 K with 200 keV Ar ions has been investigated using Rutherford backscattering spectrometry along the 〈100〉 channeling direction and compared with previous results obtained at 300 K under identical irradiation conditions. As expected, amorphization at 16 K occurs at a much lower fluence than at 300 K due to dynamic recovery of irradiation-induced defects at 300 K. Utilizing a comprehensive damage accumulation model for analysis of the data, irradiation at 16 K results only in the formation of point defects and amorphous pockets, while defect clusters are also formed at 300 K. High defect mobility under irradiation at 300 K tends to promote recombination and clustering of point defects. These results suggest that defect diffusion processes in SrTiO₃ are not thermally active at 16 K.