ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
The defect structure of radiation damage due to irradiation of Ar+ ions and the regrowth of LiTaO3 single crystal has been studied using Rutherford backscattering-channeling, cross-sectional transmission electron microscopy, optical transmittance, and surface profilometer. The irradiation were carried out at 77 K with 217 keV Ar+ ions to various doses between 3×1013 and 6×1015 Ar+/cm2. Postannealing was performed in dry O2 ambient at temperatures from 648 to 823 K, which are below Curie temperature (878 K). The optical measurement showed that the as-irradiated samples are as transparent as the unirradiated sample, indicating that the radiation-induced point defects are highly mobile even at 77 K. However, the long-range migration of oxygen interstitials were suppressed at 77 K. Volumetric expansion occurred when irradiation doses exceeded 1.25×1014 Ar+/cm2. Collective lattice distortion was observed in the sample that had received a dose of 1.5×1014 Ar+/cm2. This study shows that both disorder overlapping and the disorder-induced strain energy play important roles in the amorphization process. The regrowth of the amorphized layers depends on the microstructure of the damage. The activation energy for the regrowth of the amorphized layer that received more irradiation (6×1015 Ar+/cm2) is 0.74 eV, lower than the activation energy of the amorphized layer (1.20 eV) that received less irradiation (6×1014 Ar+/cm2). © 2002 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.1450023
