Mossbauer diffraction in single Si crystals undergoing high-frequency ultrasonic excitation. The Bragg case

Abstract
The influence of high-frequency ultrasonic waves on the dynamic diffraction of Mossbauer gamma quanta in a perfect Si crystal is studied. The scattering intensities as well as the diffractional Mossbauer spectra for different reflections and ultrasonic frequencies nu s are measured. Above the threshold frequency ( nu s> nu th), enhancement of elastic scattering is observed. At nu s< nu th, 'pumping' of the elastic component into the inelastic component occurs. The experimental data are in good agreement with the theoretical calculations.