Mössbauer isomer-shift of ferrous iron impurities in ionic and covalent binary compounds

We have developed an empirical model to determine Mössbauer isomer-shift of dilute Fe²⁺ impurities in ionic and covalent binary compounds, where at least one of the host belongs to the metalloids or non-metals category of the periodic system. The proposed approach employs the use of nearest neighbour distances and differences in host atoms Pauling electronegativity.

The two-parameter model predicts the room temperature isomer-shift of 22 compounds with room temperature isomer shifts ranging from -0.93 mm/s to +0.95 mm/s with a standard deviation of 0.09 mm/s and is valid for difference in host atoms Pauling electronegativity of ∆χ_P < 2. This provides useful information for obtaining first-hand evidence of site assignments.