Structure and magnetism of Sr3NiSb2O9

The crystal structure of the perovskite-related oxide Sr3NiSb2O9 has been refined from X-ray and neutron powder diffraction data; space group P2(1)/n, a=5.64381(2), 6=5.62299(2), c=7.95687(3) angstrom, beta=90.014(2)degrees. The structure has two crystallographically-distinct six-coordinate cation sites with occupancies Sb 0.97(1), Ni 0.03 and Sb 036, Ni 0.64. The magnetic susceptibility has been measured over the temperature range 2 <= T/K <= 300. Fitting data recorded in the temperature range 150 < T/K < 300 to the Curie-Weiss law resulted in mu(eff=)3A9(1) mu(B) per Ni2+ theta= -138(1) K. Ferrimagnetic coupling in the vicinity of the antisite defects is suggested to be responsible for the enhanced susceptibility observed below similar to 90 K. The zero-field cooled susceptibility shows a maximum at 8.7 K that is not observed in the field-cooled susceptibility. Hysteresis is observed in M(H) at 2 K but not at 7.5 K. (C) 2015 Elsevier Inc. All rights reserved.