Corrections for Non--homogeneity of the Sample in Mossbauer f-factor Measurements

We describe a procedure for correcting the systematic errors in the Mossbauer f-factor measurement due to non--homogeneous effective thickness of the sample. To be more precise, we show that, if the mass of the sample is determined by means of X or gamma-ray absorption, it is possible to establish experimental conditions so that the error on f due to material non-homogeneity in the sample is minimized.