Mossbauer isomer shifts of crystalline antimony compounds

Variations of the (121)Sb Mossbauer isomer shift delta are interpreted for different series of Sb compounds by means of a tight-binding calculation of the electron density at the nucleus rho(0). The value of the change in the mean square nuclear radius between the nuclear excited and ground states Delta[r(2)] is obtained from the correlation between the experimental values of delta and the calculated values of rho(0) for 40 Sb compounds. A good agreement with the published values is found, thus validating the present theoretical approach. The values of delta for Sb(V), Sb(III) and Sb(0) compounds are then related to the calculated values of rho(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 delta to changes in the first neighbors of Sb. (C) 2000 Elsevier Science Ltd. All rights reserved.