Antimony-121 Mössbauer Spectral Study of α-Zn_4Sb_3

Abstract

The Mössbauer spectra of α-Zn_4Sb_3, a compound that is best formulated as α-Zn_(13)Sb_(10) or (Zn^(2+))_(13)(Sb^(3-))_6(Sb_2^(4-))2, have been measured between 5 and 120 K. The resulting six spectra have been simultaneously fit with two components in the ratio of 3:2 corresponding to the Sb^(3-) and Sb^(2-) ions identified in this valence semiconductor. The fits yield temperature independent isomer shifts of −8.17(2) and −9.73(2) mm/s and quadrupole interactions of −4.9(2) and 0 mm/s for the Sb^(3-) and Sb^(2-) ions, respectively; the corresponding Mössbauer temperatures are 197(5) and 207(5) K, temperatures that are lower than the Debye temperature of β-Zn_4Sb_3. The isomer shifts correspond to electronic configurations between 5s^25p^6 and 5s^(1.75)5p^(4.01) for the Sb^(3-) ions and between 5s^25p^5 and 5s^(1.80)5p^(3.38) for the Sb^(2-) ions, configurations that are in good agreement with the expected configurations for this valence semiconductor and with the results of band structure calculations.

Additional details