Application of M\"{o}ssbauer effect to study subnanometer harmonic displacements in a thin solid

TL;DR

This study uses Mössbauer spectroscopy to measure subnanometer vibrations in thin solid samples, revealing nearly uniform vibrational amplitudes across a small irradiated spot, advancing nanoscale displacement analysis.

Contribution

The paper introduces a novel method combining Mössbauer effect and gamma-ray filtering to accurately measure and analyze subnanometer vibrations in thin solid materials.

Findings

Nuclei vibrate with amplitudes differing by only a few picometers.

The developed model effectively describes vibration spectra of powder and stainless steel samples.

Filtering gamma radiation through a small hole isolates a small vibrated spot for precise measurement.

Abstract

We measure subnanometer displacements of thin samples vibrated by piezotransducer. Samples contain $^{57}$Fe nuclei, which are exposed to 14.4 keV $\gamma$-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 picometers.