Mossbauer spectroscopy electric monopole interaction

Mossbauer spectroscopy senses the hyperfine interactions, which are present at the nucleus of the Mossbauer isotope. The electrical monopole interaction causes the isomer shift and the electric quadrupole interaction leads to the quadrupole splitting, which in the case of Fe causes a two-line Mossbauer pattern. The magnetic dipole interaction leads to a magnetically split six-line pattern (Figure 4). In the following text, these interactions and their deduction from Mossbauer spectra will be discussed. 

In Mossbauer spectroscopy, the only thing that matters is not the energy shift of an individual level, but the energy-shift difference between the ground-state and excited-state levels. Let us consider the energy shifts of the nuclear levels due to the electric monopole interaction and the energy of the y ray emitted fi-om the source and absorbed by the absorber (O Pig. 25.8). 

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