Unravelling the Elusive Antiferromagnetic Order in Wurtzite and Zinc Blende CoO Polymorph Nanoparticles

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 nanopart...

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Detalles Bibliográficos
Autores: Gómez Roca, Alejandro|||0000-0001-6610-9197, Golosovsky, I. V., Winkler, Elin, López-Ortega, Alberto|||0000-0003-3440-4444, Estrader i Bofarull, Marta|||0000-0003-3379-8234, Zysler, Roberto D., Baró, M. D.|||0000-0002-8636-1063, Nogués, Josep|||0000-0003-4616-1371
Tipo de recurso: artículo
Fecha de publicación:2018
País:España
Institución:Universitat Autònoma de Barcelona
Repositorio:Dipòsit Digital de Documents de la UAB
Idioma:inglés
OAI Identifier:oai:ddd.uab.cat:214196
Acceso en línea:https://ddd.uab.cat/record/214196
https://dx.doi.org/urn:doi:10.1002/smll.201703963
Access Level:acceso abierto
Palabra clave:Antiferromagnets
CoO wurtzite
CoO zinc blende
Incommensurate structures
Uncompensated spins
Descripción
Sumario: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.