Effect of the distribution of anisotropy constants on the magnetic properties of iron oxide nanoparticles

The distribution of shape anisotropy constants in two colloids of iron oxide nanoparticles has been measured from the distribution of particle elongations within each system. The results are in good agreement with the values calculated from a temperature decay of remanence measurement. For a fluid w...

Descripción completa

Detalles Bibliográficos
Autores: Clarke, D. M., Marquina, Clara, Lloyd, David C., Vallejo-Fernández, G.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2022
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/280229
Acceso en línea:http://hdl.handle.net/10261/280229
Access Level:acceso abierto
Palabra clave:Shape anisotropy
Magnetic hyperthermia
Iron oxide nanoparticles
Descripción
Sumario:The distribution of shape anisotropy constants in two colloids of iron oxide nanoparticles has been measured from the distribution of particle elongations within each system. The results are in good agreement with the values calculated from a temperature decay of remanence measurement. For a fluid with a saturation magnetisation of 420 emu/cc and an average particle elongation of ∼ 1.3, the distribution of energy barriers is controlled by both the distribution of particle sizes and particle elongations. For a fluid with a saturation magnetisation of 320 emu/cc and a wide distribution of particle sizes, the energy barrier to reversal can be assumed to be controlled by the distribution of particle volumes. These results highlight the need to take into account the distribution of anisotropy constants when making predictions of the heating properties of assemblies of magnetic nanoparticles for hyperthermia applications.