Structural and 121Sb Mössbauer spectroscopic investigations of the antimonide oxides REMnSbO (RE = La, Ce, Pr, Nd, Sm, Gd, Tb) and REZnSbO (RE = La, Ce, Pr)

Abstract

Quaternary antimonide oxides REMnSbO (RE = La, Ce, Pr, Nd, Sm, Gd, Tb) and REZnSbO (RE = La, Ce, Pr) were synthesized from the RESb monoantimonides and MnO, respectively ZnO, in sealed tubes at 1170 K. Single crystals were obtained from NaCl/KCl salt fluxes. The ZrCuSiAs-type (space group P4/nmm) structures of LaMnSbO (a = 423.95(7), c = 955.5(27) pm, wR2 = 0.067, 247 F2), CeMnSbO (a = 420.8(1), c = 950.7(1) pm, wR2 = 0.097, 250 F2), SmMnSbO (a = 413.1(1), c = 942.3(1) pm, wR2 = 0.068, 330 F2), LaZnSbO (a = 422.67(6), c = 953.8(2) pm, wR2 = 0.052, 259 F2), and NdZnSbO (a = 415.9(1), c = 945.4(4) pm, wR2 = 0.109, 206 F2) were refined from single crystal X-ray diffractometer data. The structures consist of covalently bonded (RE3+O2-)+ and (T2+Sb 3-)- layers with weak ionic interlayer interactions. The oxygen and transition metal atoms both have tetrahedral coordination within the layers. 121Sb Mossbauer spectra of the REMnSbO and REZnSbO compounds show single antimony sites with isomer shifts close to -8 mms-1, in agreement with the antimonide character of these compounds. PrMnSbO and NdMnSbO show transferred hyperfine fields of 8 T at 4.2 K. © 2008 Verlag der Zeitschrift für Naturforschung, Tübingen.