Application of Mossbauer effect to study subnanometer harmonic displacements in a thin solid

We measure subnanometer displacements of thin samples vibrated by piezotransducer. Samples contain 57Fe nuclei, which are exposed to 14.4 keV -radiation. Vibration produces sidebands from a single absorption line of the sample. The sideband intensities depend on the vibration amplitude and its distribution along the sample. We developed a model of this distribution, which adequately describes the spectra of powder and stainless steel (SS) absorbers. We propose to filter gamma radiation through a small hole in the mask, placed before the absorber. In this case only a small spot of the vibrated absorber is observed. We found for SS foil that nuclei, exposed to gamma radiation in this small spot, vibrate with almost the same amplitudes whose difference does not exceed a few picometer