Neutron Laue diffraction study of the complex low-temperature magnetic behaviour of brownmillerite-type Ca2Fe2O5
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Date
2015-01-01
Journal Title
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Publisher
International Union of Crystallography
Abstract
The atomic and magnetic structure of brownmillerite Ca2Fe2O5 has been refined against single-crystal neutron Laue diffraction data collected at 300, 100 and 10 K under zero-field and low-magnetic field (35 Oe = 35 × 103/4[pi] A m-1) conditions. Ca2Fe2O5 is a canted G-type antiferromagnet with Pcm'n' symmetry, the magnetic moments on Fe being directed approximately along the crystallographic c axis at room temperature. The refinement results show clearly that this magnetic structure persists down to T = 10 K, despite a previous suggestion that an anomalous magnetic susceptibility enhancement observed in Ca2Fe2O5 single crystals between 40 and 140 K might signify a reorientation of the antiferromagnetic easy axis from c to a below 40 K. Alternative explanations for this susceptibility anomaly are considered in terms of the evidence for partial or short-range loss of order in the anomalous regime, possibly due to the presence of multiple competing sublattice interactions. © International Union of Crystallography
Description
Keywords
Diffraction, Neutrons, Laue method, Antiferromagnetism, Temperature range 0065-0273 K, Monocrystals
Citation
Auckett, J. E., McIntyre, G. J., Avdeev, M., De Bruyn, H., Tan, T. T., Li, S., & Ling, C. D. (2015). Neutron Laue diffraction study of the complex low-temperature magnetic behaviour of brownmillerite-type Ca2Fe2O5. Journal of Applied Crystallography, 48, 273-279. doi:10.1107/s1600576714027976