Pendello/sung fringes in stroboscopic X-ray section topography of weakly excited quartz resonators
Abstract
The theory for slightly distorted crystals Kato (1963). J. Phys. Soc. Jpn, 18, 1785-1791 is applied to the case of quartz AT-cut resonators to interpret stroboscopic section topographs. Features in the diffraction process such as ray trajectories, phase changes and intensities of diffracted waves are drawn from this theory. Furthermore, it is shown that extra Pendello/sung fringes appearing on section topographs with increasing acoustic vibration can be directly related to the vibration amplitude within a precision of about 0-3 A. Experimental images are compared with Kato's theoretical profiles and simulated images obtained by solving Takagi's Acta Cryst. (1962), 15, 1311-1312 equations. The results lead to the conclusion that stroboscopic X-ray topography is a precise method to measure the vibration amplitude in weakly excited resonators.