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Ferroelasticity in a metal-organic framework perovskite; Towards a new class of multiferroics

Li, W., Zhang, Z., Bithell, E.G., Batsanov, A.S., Barton, P.T., Saines, P.J., Jain, P., Howard, C.J., Carpenter, M.A., Cheetham, A.K. and others. (2013) Ferroelasticity in a metal-organic framework perovskite; Towards a new class of multiferroics. Acta Materialia, 61 (13). pp. 4928-4938. ISSN 1359-6454. (doi:10.1016/j.actamat.2013.04.054) (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)

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. (Contact us about this Publication)
Official URL
http://dx.doi.org/10.1016/j.actamat.2013.04.054

Abstract

A metal-organic framework perovskite, [(CH2)3NH 2][Mn(HCOO)3], exhibits a weakly first order ferroelastic phase transition at ?272 K, from orthorhombic Pnma to monoclinic P2 1/n, and a further transition associated with antiferromagnetic ordering at ?8.5 K. The main structural changes, through the phase transition, are orientational ordering of the azetidium groups and associated changes in hydrogen bonding. In marked contrast to conventional improper ferroelastic oxide perovskites, the driving mechanism is associated with the X-point of the cubic Brillouin zone rather than being driven by R- and M-point octahedral tilting. The total ferroelastic shear strain of up to ?5% is substantially greater than found for typical oxide perovskites, and highlights the potential of the flexible framework to undergo large relaxations in response to local structural changes. Measurements of elastic and anelastic properties by resonant ultrasound spectroscopy show some of the characteristic features of ferroelastic materials. In particular, acoustic dissipation below the transition point can be understood in terms of mobility of twin walls under the influence of external stress with relaxation times on the order of ?10-7 s. Elastic softening as the transition is approached from above is interpreted in terms of coupling between acoustic modes and dynamic local ordering of the azetidium groups. Subsequent stiffening with further temperature reduction is interpreted in terms of classical strain-order parameter coupling at an improper ferroelastic transition which is close to being tricritical. By way of contrast, there are no overt changes in elastic or anelastic properties near 9 K, implying that any coupling of the antiferromagnetic order parameter with strain is weak or negligible.

Item Type: Article
DOI/Identification number: 10.1016/j.actamat.2013.04.054
Uncontrolled keywords: Ferroelasticity, Metal-organic framework, Perovskite, Phase transition, Resonant ultrasound spectroscopy, Antiferromagnetic order parameter, Antiferromagnetic orderings, Ferroelastic materials, Ferroelastic phase transition, Ferroelasticity, Metal organic framework, Orientational orderings, Resonant Ultrasound Spectroscopy, Antiferromagnetism, Crystalline materials, Hydrogen bonds, Phase transitions, Spectroscopy, Perovskite
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 15:23 UTC
Last Modified: 29 May 2019 16:04 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/50718 (The current URI for this page, for reference purposes)
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