Overview

Source: Joshua Wofford, Tamara M. Powers, Department of Chemistry, Texas A&M University

Mössbauer spectroscopy is a bulk characterization technique that examines the nuclear excitation of an atom by gamma rays in the solid state. The resulting Mössbauer spectrum provides information about the oxidation state, spin state, and electronic environment around the target atom, which, in combination, gives evidence about the electronic structure and ligand arrangement (geometry) of the molecule. In this video, we will learn about the basic principles of Mössbauer spectroscopy and collect a zero field ⁵⁷Fe Mössbauer spectrum of ferrocene.

Procedure

1. Preparation of the Sample

Weigh 100 mg of ferrocene in a delrine Mössbauer cup.
Add several drops of paratone oil to the sample. Using a spatula, mix the sample and the oil into a uniform paste.
Freeze the sample in liquid nitrogen.

2. Mounting the Sample

Fill the sample chamber with He gas.
Unscrew the sample rod from the instrument and remove the sample rod.
While mounting the sample, close the sample chamber with

Log in or to access full content. Learn more about your institution’s access to JoVE content here

Results

Zero field ⁵⁷Fe Mössbauer of ferrocene at 5 K.

δ = 0.54 mm/s

ΔE_Q = 2.4 mm/s

Referring to Table 1, we see that the isomer shift at 0.54 mm/s falls into several possible oxidation state/spin state ranges (

Log in or to access full content. Learn more about your institution’s access to JoVE content here

Application and Summary

Here, we learned about the basic principles of Mössbauer spectroscopy, including details on the experimental setup, the gamma ray source, and the information that can be gathered from a Mössbauer spectrum. We collected the zero field ⁵⁷Fe Mössbauer spectrum of ferrocene.

Mössbauer spectroscopy is a powerful technique that provides information about the electronic field gradient around an atom. While there are numerous Mössbauer active atoms, only elements wi

Log in or to access full content. Learn more about your institution’s access to JoVE content here

References

Fultz, B. “Mössbauer Spectrometry”, in Characterization of Materials. John Wiley. New York. (2011).
Pandelia, M.-E., Lanz, N., Booker, S., Krebs, C. Mössbauer spectroscopy of Fe/S proteins Biochim Biophys Acta. 1853, 1395–1405 (2015).

Mössbauer Spectroscopy