Mِssbauer isomer shifts of crystalline antimony compounds

Variations of the 121Sb Mössbauer isomer shift δ are interpreted for different series of Sb compounds by means of a tight-binding calculation of the electron density at the nucleus ρ(0). The value of the change in the mean square nuclear radius between the nuclear excited and ground states Δ〈r2〉 is obtained from the correlation between the experimental values of δ and the calculated values of ρ(0) for 40 Sb compounds. A good agreement with the published values is found, thus validating the present theoretical approach. The values of δ for Sb(V), Sb(III) and Sb(0) compounds are then related to the calculated values of ρ(0) and the electronic numbers of Sb 5s and 5p electrons. Finally, a discussion is proposed for the Sb(V) compounds and for a series of Sb(0) compounds in order to relate the observed variations of δ to changes in the first neighbors of Sb.