PLATINUM IMPLANTED LITHIUM-NIOBATE - ANNEALING BEHAVIOR AND DOPANT REDISTRIBUTION

The recrystallization and dopant redistribution of lithium niobate (Li NbO3) implanted with 50 keV Pt+ ions to a fluence of 5 x 10(16) cm(-2) at room temperature was studied using Rutherford backscattering spect roscopy (RBS)/channeling and optical absorption measurements. It was f ound that the redistribution mechanisms for the Pt implant strongly de pend on the annealing temperature and duration as well as on the therm al history of the sample. Segregation of Pt was detected for annealing at 600 degrees C (independent of the annealing time) and at 800 degre es C (for annealing times up to 4 h), while diffusion was observed for longer annealing times at 800 degrees C and at 1000 degrees C. The Pt diffusion was strongly hampered in the case of the incrementally anne aled sample. RBS/channeling and optical absorption measurements sugges t the existence of Pt aggregates. The LiNbO3 host lattice recovered pa rtly during annealing at temperatures up to 800 degrees C, while full recovery is achieved only at after annealing at 1000 degrees C and is accompanied by a drastic reduction of the Pt concentration. (C) 1998 E lsevier Science B.V. All rights reserved.