Ferrimagnetism as a Consequence of Unusual Cation Ordering in the Perovskite SrLa2FeCoSbO9

• Published in: Inorganic chemistry 2018-06, Vol.57 (12), p.7438-7445
• Main Authors: Tang, Yawei, Hunter, Emily C, Battle, Peter D, Hendrickx, Mylène, Hadermann, Joke, Cadogan, J. M
• Format: Article
• Language: English
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/acs.inorgchem.8b01012

A polycrystalline sample of SrLa2FeCoSbO9 has been prepared in a solid-state reaction and studied by a combination of electron microscopy, magnetometry, Mössbauer spectroscopy, X-ray diffraction, and neutron diffraction. The compound adopts a monoclinic (space group P21/n; a = 5.6218(6), b = 5.6221(6), c = 7.9440(8) Å, β = 90.050(7)° at 300 K) perovskite-like crystal structure with two crystallographically distinct six-coordinate sites. One of these sites is occupied by 2/3 Co2+, 1/3 Fe3+ and the other by 2/3 Sb5+, 1/3 Fe3+. This pattern of cation ordering results in a transition to a ferrimagnetic phase at 215 K. The magnetic moments on nearest-neighbor, six-coordinate cations align in an antiparallel manner, and the presence of diamagnetic Sb5+ on only one of the two sites results in a nonzero remanent magnetization of ∼1 μB per formula unit at 5 K.