Published Online: 15 DEC 2009
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Encyclopedia of Applied Physics
How to Cite
Yang, D.-P. 2009. Mössbauer Spectroscopy. Encyclopedia of Applied Physics. 51–85.
- Published Online: 15 DEC 2009
Mössbauer spectroscopy is a unique technique based on nuclear resonance via recoil-free emission, absorption, and scattering of γ-rays. Because of its extremely high energy resolution and its particular timescale, a Mössbauer spectrum can provide valuable information on structural, chemical, magnetic, and dynamical properties of a variety of solid materials. Mössbauer spectroscopy finds applications in various fields of scientific research, such as physics, metallurgy, materials science, chemistry, mineralogy, biology, medicine, environmental science, archeology, and art.
Mössbauer effect has been observed in about 100 isotopes. 57Fe is by far the most important one, followed by 119Sn. A typical Mössbauer spectrometer operates in the transmission geometry where the γ-rays emitted from the source and modulated via Doppler effect are resonantly absorbed in a solid sample. The amount of transmitted γ-rays is recorded and analyzed as a function of γ-photon energy, resulting in a Mössbauer spectrum. The shape, location, and intensity of the absorption peaks in a Mössbauer spectrum can reveal hyperfine interactions between the Mössbauer isotope and its surroundings, and therefore provide information on the chemical, magnetic, and structural properties of the material under investigation.
The emission, absorption, and scattering of γ-rays may also involve the creation or annihilation of phonons. This process is intricately related to lattice dynamics and strongly dependent on temperature. Therefore, Mössbauer spectroscopy can be used for studying lattice vibrations and phonon density of states, as well as their dependence on temperature, pressure, crystallinity, impurity, and so on.
As synchrotron radiation became available, new elastic and inelastic scattering methods have been developed. The emergence of time-domain Mössbauer spectroscopy has provided not only evidence for the coherent decay of nuclear excitons but also a new methodology for extracting parameters of hyperfine interactions and lattice dynamics.
- Mössbauer spectroscopy;
- hyperfine interactions;
- nuclear resonance;
- synchrotron radiation;
- phonon density of states