Double-crystal diffraction imaging with a small effective divergence source: application to the magneto-acoustic vibrations in FeBO3

Ultrasonic standing waves, excited in FeBO3 (111) crystal plates through magnetoelastic coupling, have been visualized using monochromatic Bragg diffraction imaging (topography) employing synchrotron radiation. The images depend strongly on whether diffraction by the sample occurs in the same plane as in the double-crystal monochromator, or in the perpendicular plane.