Nuclear Bragg Diffraction of Synchrotron Radiation in the Presence of Acoustic Vibrations

The time evolution of nuclear Bragg diffraction of 14.4 keV synchrotron radiation in a5?FeBO, crystal was studied when the crystal was excited to magnetoelastic vibrations by a r.f. fieldof 2.93MH2. The vibrations did not modifu the time evolution of the diffraction. This result is due tothe fact that after the excitation by the SR pulse the nuclear vibrations cause only a phase modulationof the re-emitted radiation. Energy spectra, by contrast, are extremely sensitive to vibrations. Thusthe present case is an instructive example of complementarity between energy and time domainMôssbauer spectroscopy. Time domain spectroscopy, inparticular, will allow to reveal phenomena,which are blured in the energy spectra by vibratio