Gray track formation in KTiOPO4 by swift ion irradiation

Potassium titanyl phosphate single crystals were irradiated with 48 MeV lit hium ions at fluences varying from 5 x 10(12) to 10(16) ions/cm(2). The def ects created in the crystal have been characterized using x-ray rocking cur ve measurements, optical transmittance, and photoluminescence spectroscopy. From x-ray rocking curve studies, the full width at half maximum for the i rradiated samples was observed to increase, indicating lattice strain cause d by the energetic ions. Optical transparency of these samples was found to decrease upon irradiation. The irradiated samples exhibited a broadband lu minescence in the 700-900 nm region, for fluences above 5 x 10(13) ions/cm( 2). The results indicate that ion-beam-induced optical effects in KTiOPO4 s ingle crystals are very similar to the ones obtained for crystals with "gra y tracks," which are attributed to the electronic transitions in the Ti3+ l evels. (C) 2001 American Institute of Physics.