Longitudinal domain wall formation in elongated assemblies of ferromagnetic nanoparticles

Through evaporation of dense colloids of ferromagnetic ∼13nm Ɛ-Co particles onto carbon substrates, anisotropic magnetic dipolar interactions can support formation of elongated particle structures with aggregate thicknesses of 100-400â €‰nm and lengths of up to some hundred microns. Lorenz microscop...

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Detalles Bibliográficos
Autores: Varón Izquierdo, Miriam, Beleggia, Marco, Jordanovic, Jelena, Schiøtz, Jakob, Kasama, Takeshi, Puntes, Víctor|||0000-0001-8996-9499, Frandsen, Cathrine
Tipo de recurso: artículo
Fecha de publicación:2015
País:España
Institución:Universitat Autònoma de Barcelona
Repositorio:Dipòsit Digital de Documents de la UAB
Idioma:inglés
OAI Identifier:oai:ddd.uab.cat:204906
Acceso en línea:https://ddd.uab.cat/record/204906
https://dx.doi.org/urn:doi:10.1038/srep14536
Access Level:acceso abierto
Palabra clave:Magnetic devices
Magnetic properties and materials
Descripción
Sumario:Through evaporation of dense colloids of ferromagnetic ∼13nm Ɛ-Co particles onto carbon substrates, anisotropic magnetic dipolar interactions can support formation of elongated particle structures with aggregate thicknesses of 100-400â €‰nm and lengths of up to some hundred microns. Lorenz microscopy and electron holography reveal collective magnetic ordering in these structures. However, in contrast to continuous ferromagnetic thin films of comparable dimensions, domain walls appear preferentially as longitudinal, i.e., oriented parallel to the long axis of the nanoparticle assemblies. We explain this unusual domain structure as the result of dipolar interactions and shape anisotropy, in the absence of inter-particle exchange coupling.