Polarimetry in M\"ossbauer spectroscopy with Synchrotron M\"ossbauer Source

TL;DR

This paper demonstrates a novel polarization analysis technique in Mossbauer spectroscopy using Synchrotron sources, revealing new insights into magnetic and dichroic effects with enhanced surface sensitivity.

Contribution

The study introduces the use of polarization analysis of reflected radiation in Mossbauer spectroscopy with Synchrotron sources, highlighting the detection of rotated polarization components and their angular dependence.

Findings

Rotated polarization components create distinct spectral features near the critical angle.

Reflected spectra with polarization analysis differ significantly from traditional spectra.

The technique enhances surface sensitivity and simplifies spectral interpretation.

Abstract

We have tested the new experimental techniques in the M\"ossbauer spectroscopy with Synchrotron M\"ossbauer Source by using the polarization analysis of the reflected radiation. In particular we have shown that the dichroic components in M\"ossbauer spectra create the scattering intensity with "rotated" polarization. The angular dependence for such component in the reflected signal is characterized by the peak near the critical angle of the total external reflection, and in the case of the collinear antiferromagnetic interlayer ordering the "magnetic" maxima on the reflectivity curve are formed mainly by this "rotated" polarization. The first experiment on M\"ossbauer reflectivity with selection of the "rotated" polarization shows the expected peak near the critical angle. The measured M\"ossbauer reflectivity spectra of the "rotated" polarization near the critical angle are rather different from the M\"ossbauer reflectivity spectra, measured without polarization analysis. They contain a smaller number of lines and can simplify the interpretation of the poorly resolved spectra. The enhanced surface sensitivity of the new technique is discussed.