Synthesis, structure, magnetism and cation ordering in Ba3-Sr Fe2O5Cu2Ch2 (x = 0, 1, 2; Ch = S, Se) and BaCa2Fe2O5Cu2S2

DOI: 10.1016/j.jssc.2021.122841

Authors: Robert D. Smyth (University of Oxford) , John A. D. Wilson (University of Oxford) , Pascal Manuel (ISIS Facility) , Simon J. Clarke (University of Oxford)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Journal Of Solid State Chemistry , VOL 15

State: Published (Approved)
Published: December 2021
Diamond Proposal Number(s): 18786 , 25166

Abstract: The layered oxide chalcogenides Ba3-xSrxFe2O5Cu2Ch2 (x = 0, 1, 2; Ch = S, Se) and BaCa2Fe2O5Cu2S2 are reported here for the first time. They are isostructural with the previously reported Sr3Fe2O5Cu2Ch2, crystallising in the I4/mmm space group. This structure is related to the n = 2 Ruddlesden-Popper type structure which is common for oxides and contains Sr3Fe2O5 perovskite-related slabs intergrown with Cu2Ch2 layers which resemble fragments of the antifluorite structure. In the oxide slabs, a double layer of FeO5 pyramids is formed by the sharing of apical oxide ions. Structural analysis shows a clear partial ordering of the alkaline earth cations of different sizes over the available 12 and 8-coordinate sites which correlates with the size variation of the alkaline earth cations. Long range magnetic ordering on a √2a × √2a × c expansion of the nuclear cell reveals nearest neighbour Fe3+ moments coupling antiferromagnetically via all the Fe–O–Fe linkages. In Ba3Fe2O5Cu2Se2, the moments are oriented in the ab-plane, whereas in Ba3-xSrxFe2O5Cu2Ch2 (x = 2; Ch = S, Se), the Fe3+ moments are tilted towards the c-axis, reflecting that high spin d5 ions with no orbital angular momentum have only a weak preference for a particular spin direction.

Journal Keywords: Oxide chalcogenide; Magnetic ordering; Cation ordering

Subject Areas: Chemistry, Materials, Physics


Instruments: I11-High Resolution Powder Diffraction

Other Facilities: WISH at ISIS

Added On: 29/12/2021 09:04

Discipline Tags:

Physics Physical Chemistry Chemistry Magnetism Materials Science Inorganic Chemistry

Technical Tags:

Diffraction X-ray Powder Diffraction