Elastic and anelastic anomalies associated with the antiferromagnetic ordering transition in wüstite, Fe xO

Zhang, Z. and Church, N. and Lappe, S.-C. and Reinecker, M. and Fuith, A. and Saines, P.J. and Harrison, R.J. and Schranz, W. and Carpenter, M.A. (2012) Elastic and anelastic anomalies associated with the antiferromagnetic ordering transition in wüstite, Fe xO. Journal of Physics Condensed Matter, 24 (21). p. 953. ISSN 0953-8984. (doi:https://doi.org/10.1088/0953-8984/24/21/215404) (The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided)

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Official URL
http://dx.doi.org/10.1088/0953-8984/24/21/215404

Abstract

The elastic and anelastic properties of three different samples of Fe xO have been determined in the frequency range 0.12MHz by resonant ultrasound spectroscopy and in the range 0.150Hz by dynamic mechanical analysis in order to characterize ferroelastic aspects of the magnetic ordering transition at T N195K. No evidence was found of separate structural and magnetic transitions but softening of the shear modulus was consistent with the involvement of bilinear coupling, λe 4q, between a symmetry-breaking strain, e 4, and a structural order parameter, q. Unlike a purely ferroelastic transition, however, C 44 does not go to zero at the critical temperature" due to the intervention of the magnetic ordering at a higher temperature. The overall pattern of behaviour is nevertheless consistent with what would be expected for a system with separate structural and magnetic instabilities, linearquadratic coupling between the structural (q) and magnetic (m) driving order parameters, ?qm 2, and . Comparison with data from the literature appears to confirm the same pattern in MnO and NiO, with a smaller difference between T N and in the former and a larger difference in the latter. Strong attenuation of acoustic resonances at high frequencies and a familiar pattern of attenuation at low frequencies suggest that twin walls in the rhombohedral phase have typical ferroelastic properties. Acoustic dissipation in the stability field of the cubic phase is tentatively attributed to anelastic relaxations of the defect ordered structure of non-stoichiometric wüstite or of the interface between local regions of wüstite and magnetite, with a rate controlling step determined by the diffusion of iron.

Item Type: Article
Uncontrolled keywords: Acoustic dissipation, Acoustic resonance, Anelastic properties, Antiferromagnetic orderings, Bilinear coupling, Critical temperatures, Cubic phase, Diffusion of iron, Ferroelastics, Frequency ranges, High frequency, Higher temperatures, Local region, Low frequency, Magnetic instability, Magnetic ordering transitions, Magnetic transitions, Order parameter, Ordered structures, Rate-controlling steps, Resonant Ultrasound Spectroscopy, Rhombohedral phase, Structural order parameter, Symmetry-breaking, Twin walls, Antiferromagnetism, Manganese oxide, Separation, ferrous ion, ferrous oxide, article, chemistry, hardness, magnetic field, materials testing, phase transition, Young modulus, Elastic Modulus, Ferrous Compounds, Hardness, Magnetic Fields, Materials Testing, Phase Transition
Subjects: Q Science > QC Physics > QC173.45 Condensed Matter
Q Science > QD Chemistry > QD478 Solid State Chemistry
Divisions: Faculties > Sciences > School of Physical Sciences > Functional Materials Group
Depositing User: Paul Saines
Date Deposited: 06 Oct 2015 16:01 UTC
Last Modified: 07 Oct 2015 09:54 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/50725 (The current URI for this page, for reference purposes)
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