Unravelling the Elusive Antiferromagnetic Order in Wurtzite and Zinc Blende CoO Polymorph Nanoparticles
Gómez Roca, Alejandro (Institut Català de Nanociència i Nanotecnologia)
Golosovsky, I. V. (Peterburgskiĭ institut i︠a︡dernoĭ fiziki im. B.P. Konstantinova)
Winkler, Elin (Centro Atómico Bariloche)
López Ortega, Alberto (CIC nanoGUNE)
Estrader, Marta (Institut Català de Nanociència i Nanotecnologia)
Zysler, Roberto D. (Centro Atómico Bariloche)
Baró, M. D. (Universitat Autònoma de Barcelona. Departament de Física)
Nogués i Sanmiquel, Josep (Institut Català de Nanociència i Nanotecnologia)

Date:	2018
Abstract:	Although cubic rock salt-CoO has been extensively studied, the magnetic properties of the main nanoscale CoO polymorphs (hexagonal wurtzite and cubic zinc blende structures) are rather poorly understood. Here, a detailed magnetic and neutron diffraction study on zinc blende and wurtzite CoO nanoparticles is presented. The zinc blende-CoO phase is antiferromagnetic with a 3rd type structure in a face-centered cubic lattice and a Néel temperature of T (zinc-blende) ≈225 K. Wurtzite-CoO also presents an antiferromagnetic order, T (wurtzite) ≈109 K, although much more complex, with a 2nd type order along the c-axis but an incommensurate order along the y-axis. Importantly, the overall magnetic properties are overwhelmed by the uncompensated spins, which confer the system a ferromagnetic-like behavior even at room temperature.
Note:	Altres ajuts: Beatriu de Pinos Fellowship (ref 2011 BP_B 00209)
Note:	Número d'acord de subvenció AGAUR/2017/SGR-292
Note:	Número d'acord de subvenció MINECO/IJCI‐2014‐21530
Note:	Número d'acord de subvenció MINECO/SEV-2013-0295
Rights:	Tots els drets reservats.
Language:	Anglès.
Document:	article ; recerca ; submittedVersion
Subject:	Antiferromagnets ; CoO wurtzite ; CoO zinc blende ; Incommensurate structures ; Uncompensated spins
Published in:	Small, Vol. 14, Issue 15 (April 2018) , art. 1703963, ISSN 1613-6829

DOI: 10.1002/smll.201703963

Preprint 33 p, 4.8 MB

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Research literature > UAB research groups literature > Research Centres and Groups (scientific output) > Experimental sciences > Catalan Institute of Nanoscience and Nanotechnology (ICN2)
Articles > Research articles
Articles > Published articles