A comprehensive study of magnetic exchanges in the layered oxychalcogenides Sr3Fe2O5Cu2Q2 (Q = S, Se)

[摘要] The layered oxysulfide Sr3Fe2O5Cu2S2 was prepared, and its crystal structure and magnetic properties were characterized by synchrotron X-ray diffraction (XRD), powder neutron diffraction (PND), Mssbauer spectroscopy measurements and by density functional theory (DFT) calculations. In addition, the spin exchange interactions leading to the ordered magnetic structure of Sr3Fe2O5Cu2S2 were compared with those of its selenium analogue Sr3Fe2O5Cu2Se2. The oxysulfide Sr3Fe2O5Cu2S2 adopts a Gtype antiferromagnetic (AFM) structure at a temperature in the range 485-512 K, which is comparable with the three-dimensional (3D) AFM ordering temperature, TN approximate to 490 K, found for Sr3Fe2O5Cu2S2. Consistent with this observation, the spin exchange interactions of the magnetic (Sr3Fe2O5)(2+) layers are slightly greater (but comparable) for oxysulfide than for the oxyselenide. Attempts to reduce or oxidize Sr3Fe2O5Cu2S2 using topochemical routes yield metallic Fe. (C) 2017 Elsevier B.V. All rights reserved.

[发布日期] 2017-12-15

[关键词] Layered oxychalcogenides;Antiferromagnetism;Mossbauer;Neutron diffraction;Magnetic structure