MOSSBAUER SPECTROSCPY

Vijaya Durga* and Chandana and Padmalatha

ABSTRACT

Mossbauer spectrometry provides unique measurements of electronic, magnetic, and structural properties within materials. A Mossbauer spectrum is an intensity of γ-ray absorption versus energy for a specific resonant nucleus such as 57Fe or 119Sn. Mossbauer spectrometry looks at materials from the “inside out,” where “inside” refers to the resonant nucleus. For one nucleus to emit a γ-ray and a second nucleus to absorb it with efficiency, both nuclei must be embedded in solids, a phenomenon known as the “Mossbauer effect.” Mossbauer spectra give quantitative information on “hyperfine interactions,” which are small energies from the interaction between the nucleus and its neighbouring electrons. The three important hyperfine interactions originate from the electron density at the nucleus (the isomer shift), the gradient of the electric field (the nuclear quadrupole splitting), and the unpaired electron density at the nucleus (the hyperfine magnetic field). Over the years, methods have been refined for using these three hyperfine interactions to determine valence and spin at the resonant atom. Even when the hyperfine interactions are not easily interpreted, they can often be used reliably as “fingerprints” to identify the different local chemical environments of the resonant atom, usually with a good estimate of their fractional abundances. Mossbauer spectrometry is useful for quantitative phase analyses or determinations of the concentrations of resonant element in different phases, even when the phases are nanostructured or amorphous.

Keywords: Mossbauer spectroscopy, Mossbauer Effect, Mossbauer spectroscopy with synchrotron radiation, Nuclear forward scattering, Nuclear in-elastic scattering, Sample preparation.