Imaging of implantation defects by X-ray topography combined with surface acoustic wave excitation

Abstract

X-ray topographs of the He-implanted LiNbO 3 crystals under 10 μm-surface acoustic wave excitation were taken using monochromatized synchrotron radiation provided by the European Synchrotron Radiation Facility (ESRF, Grenoble). Measurements were made in the stroboscopic mode, i.e. by synchronizing the electron bunch frequency with the resonant frequency of the acoustic wave excitation in the 300 MHz range. These X-ray diffraction images showed plane acoustic wave propagation through the LiNbO 3 crystals as well as wave front distortions due to scattering by extended defects. Secondary spherical waves were observed for the first time as a result of the strong interaction between the acoustic waves and the sub-micron size density perturbations.