Simultaneous individual and dipolar collective properties in binary assemblies of magnetic nanoparticles

Applications based on aggregates of magnetic nanoparticles are becoming increasingly widespread, ranging from hyperthermia to magnetic recording. However, although some uses require collective behavior, others need a more individual-like response, the conditions leading to either of these behaviors...

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Detalles Bibliográficos
Autores: Sánchez, Elena H.|||0000-0001-5737-0035, Vasilakaki, Marianna, Lee, Su Seong, Normile, Peter S., Muscas, Giuseppe, Murgia, Massimiliano, Andersson, Mikael S., Singh, Gurvinder, Mathieu, Roland|||0000-0002-5261-2047, Nordblad, Per, Ricci, Pier Carlo|||0000-0001-6191-4613, Peddis, Davide|||0000-0003-0810-8860, Trohidou, Kalliopi N., Nogués, Josep|||0000-0003-4616-1371, De Toro, José A.|||0000-0002-9075-1697
Tipo de recurso: artículo
Fecha de publicación:2020
País:España
Institución:Universitat Autònoma de Barcelona
Repositorio:Dipòsit Digital de Documents de la UAB
Idioma:inglés
OAI Identifier:oai:ddd.uab.cat:236022
Acceso en línea:https://ddd.uab.cat/record/236022
https://dx.doi.org/urn:doi:10.1021/acs.chemmater.9b03268
Access Level:acceso abierto
Palabra clave:Anisotropy energies
Collective behavior
Collective properties
Different proportions
Dipolar interaction
Dipolar systems
High anisotropy
Specific properties
Descripción
Sumario:Applications based on aggregates of magnetic nanoparticles are becoming increasingly widespread, ranging from hyperthermia to magnetic recording. However, although some uses require collective behavior, others need a more individual-like response, the conditions leading to either of these behaviors are still poorly understood. Here, we use nanoscale-uniform binary random dense mixtures with different proportions of oxide magnetic nanoparticles with low/high anisotropy as a valuable tool to explore the crossover from individual to collective behavior. Two different anisotropy scenarios have been studied in two series of binary compacts: M1, comprising maghemite (γ-Fe2O3) nanoparticles of different sizes (9.0 nm/11.5 nm) with barely a factor of 2 between their anisotropy energies, and M2, mixing equally sized pure maghemite (low-anisotropy) and Co-doped maghemite (high-anisotropy) nanoparticles with a large difference in anisotropy energy (ratio.