The method of invariants in 57Fe Mössbauer spectroscopy on selected examples

The method of invariants is an effective tool for decomposition of Mossbauer spectra into components resulting from electric quadrupole and magnetic dipole interactions. The invariants can be next analysed to obtain all possible values of hyperfine interaction parameters. In some cases it is possible to determine the parameters with satisfactory precision. The method was applied to not fully ordered UFe4Al8. Obtained results indicate that the dominant component of the electric field gradient is negative and is oriented almost perpendicularly to the direction of the hyperfine magnetic field. Another example shows that the method of invariants results in substantial reduction of the number of calculated components in modeling of hyperfine interactions in γ-FeMn.