INVESTIGATION OF DEFECTS IN KTIOPO4 AFTER INDIUM IMPLANTATION AND DIFFUSION

Perturbed angular correlation spectroscopy (PACS) was used for the fir st time to study electric field gradients (EFG) in the local electroni c environment of indium probe atoms in KTiOPO4. Annealing at 1073 K bo th in oxygen and argon atmosphere leads to the formation of EFG1 in bo th types of samples and to three additional EFGs in argon annealed sam ples only. Below 1073 K the annealing behaviour in both cases is nearl y identical. High temperature measurements in oxygen atmosphere rangin g from room-temperature up to T-measure = 1216 K reveal that starting from T-measure = 1071 K about 50% of the probe atoms are exposed to on e EFG only, namely EFG1. This behaviour is dramatically different from the room-temperature situation. A comparison between samples diffused by In-111 probe atoms and with implanted probes shows that the measur ed effects are not due to radiation damage.