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Ryan D.H.,McGill University | Legros A.,McGill University | Niehaus O.,University of Munster | Pottgen R.,University of Munster | And 2 more authors.
Journal of Applied Physics | Year: 2015

Neutron powder diffraction confirms that the primary ordering mode in Eu4PdMg is ferromagnetic with a europium moment of 6.5(2) μB. 151Eu Mössbauer spectroscopy shows that the unusual linear temperature dependence of the magnetisation reported for this system is an intrinsic property and not an artefact of the applied field. The form and temperature evolution of the 151Eu Mössbauer spectra strongly suggest that there is an incommensurate modulation to the magnetic structure that modifies the basic ferromagnetic order. This modulated structure may be the origin of the broad magnetocaloric response previously observed in Eu4PdMg. © 2015 AIP Publishing LLC.

Cadogan J.M.,UNSW Canberra at the Australian Defence Force Academy | Ryan D.H.,McGill University | Rejali R.,McGill University | Boyer C.D.,Chalk River Laboratories
Journal of Alloys and Compounds | Year: 2016

The magnetic ordering of the trigonal compound EuGe2 has been studied using 151Eu Mössbauer spectroscopy and neutron powder diffraction. The europium in EuGe2 is divalent and orders antiferromagnetically (AF) below TN∼49 K giving a hyperfine field of 24.4(1) T at 4.6 K. The thermal evolution of the spectra shows no evidence for changes to the structure or slow paramagnetic dynamics as TN is approached from below. Analysis of the neutron diffraction data shows that EuGe2 orders as an A-type AF with the 7.1(2)μB Eu2+ moments ordered as ferromagnetic sheets within the ab-plane and AF coupled along the c-axis, forming a magnetic cell that is doubled along the crystallographic c-axis. © 2016 Elsevier B.V.

Cadogan J.M.,UNSW Canberra at the Australian Defence Force Academy | Devlin E.J.,Advanced Materials and Processes
Hyperfine Interactions | Year: 2014

Nurina-003 is a Group LL5/br Ordinary Chondrite meteorite which was recovered in the Nullarbor Desert (Australia) in 1986. The degree of weathering is classified as moderate to severe. We have characterised the Fe-bearing phases in Nurina-003 by 57Fe Mössbauer Spectroscopy over the temperature range 5-295 K. The spectra are dominated by Olivine and also contain Pyroxene, Troilite and a Ferric component that is (super)paramagnetic at 295 K. We clearly see the effects of the magnetic ordering of the Olivine phase in the 5 K spectrum. © 2013 Springer Science+Business Media Dordrecht.

Ryan D.H.,McGill University | Cadogan J.M.,UNSW Canberra at the Australian Defence Force Academy
Hyperfine Interactions | Year: 2014

The closed-shell, well-screened europium moment should make its compounds an easy and robust system in which to study the correlation between the local moment and the observed hyperfine field (Bhf). Having explored why one might expect Bhf to provide a reasonable measure of the local moment, and why the isomer shift (δ) might allow for a first-order correction to include the effects of the local chemical environment, we proceed with an anlysis of the extensive 151Eu Mössbauer data on the EuT2X2 compound family. We find that while in some limited cases a useful correlation may exist, in general there are far too many as yet unknown contributions to Bhf for it to provide a meaningful estimate of the moment. © 2013 Springer Science+Business Media Dordrecht.

Hynes M.,Australian National University | Sharpe S.,UNSW Canberra at the Australian Defence Force Academy
Cultural Geographies | Year: 2015

Contributing to cultural geography’s emerging interest in the work of Felix Ravaisson, this article explores the relationship between the impersonal force of habit and the personalised production of subjectivity. More precisely, our concern is with the relationship between habit and the stylisation of self that can be witnessed in the production of the intellectual subject. Paying particular attention to the relationship he traces between habit, consciousness and the effort that defines subjectivity, we explore the implications of Ravaisson’s understanding of habit for the work of style, understood as an integration of habits and dispositions into a manner of being. By exploring the question of intellectual style in the work of Alain Badiou, Michel Foucault and Friedrich Nietzsche, we consider what the implications might be of performing that task of integration lightly, without the lofty weightiness that often attends intellectual life. © The Author(s) 2014.

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