The influence of stopping power and temperature on latent track formation in YAP and YAG

Abstract

Transmission electron microscopy techniques were used to analyse the effect of swift heavy ion irradiation on both yttrium aluminium perovskite (YAP) YAlO3, and yttrium aluminium garnet (YAG) Y3Al5O12 single crystals. The crystals were irradiated with Kr, Xe and Bi ions with energies ranging from 107 to 1030 MeV. These ions have electronic stopping powers in the range from 11 to 41 keV/nm. The ion fluences were all within the non-overlapping regime for latent ion tracks i.e. 1011–1012 cm−2. A number of crystals were also irradiated at different temperatures of 80, 300 and 1000 K at a fixed stopping power. Latent ion tracks with an amorphous core were observed in all samples. The track diameters were seen to increase with increasing stopping power. Track diameters only increase by a significant amount as a result of irradiation temperature at 1000 K, whereas the diameters at 80 and 300 K differ only slightly. Ion tracks in YAG were also found to be larger than those in YAP at comparable stopping powers. It was found that on average 10 keV/nm of extra energy input is required to produce ion tracks in YAP with diameters similar to those in YAG. The results also suggest that the complexity of the crystal structure plays a significant role in the formation of ion tracks in these crystals.