Comparison of kinematic X-ray diffraction and backscattering spectrometry — strain and damage profiles in garnet

Abstract

We compare the results of measurements of crystal distortions made by means of two techniques: a new kinematic X-ray diffraction technique and backscattering spectrometry of channeled MeV ions. Samples were 〈111〉 single-crystal gadolinium gallium garnet (GGG) that had been implanted at room temperature with 100 keV Ne + ions to various doses. For these implantation conditions, the ranges of sensitivity of the two techniques overlap for about one decade in implantation dose up to the amorphous threshold. X-ray diffraction was found to be most sensitive to low damage levels while backscattering was found to be most sensitive to high damage levels. Neither method as applied here is sensitive to light atoms in a heavy matrix. In the former technique, strain and damage profiles were obtained by fitting a model to the X-ray rocking curve. In the latter technique, the damage profile was obtained directly from the energy spectrum of backscattered particles while strain was obtained from the implantation-induced changes in the relative orientations of channeling axes. The two techniques are in excellent agreement on the near-surface strain, but differ significantly at depths below ∼500 A ̊ . The damage distributions agree to within a factor of 2.