Determination of hyperfine interaction parameters from poorly resolved Moessbauer spectra with the transmission integral

For badly resolved Moessbauer spectra of 61Ni and 121Sb it is demonstrated that even for moderate thickness the analysis with a sum of Lorentzians instead of the complete transmission integral may introduce significant deviations in determining hyperfine interaction constants. Graphs with the relative deviations for purely magnetic and quadrupolar interactions are shown. From these plots it is indicated when the use of the complete transmission integral is recommended. (orig.)