Mössbauer isomer shifts of crystalline antimony compounds

Variations of the 121 Sb Mossbauer 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〈 r 2 〉 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.