Size effects in the magneto-optical response of Co nanoparticles

A study of the magneto-optical (MO) spectral response of Co nanoparticles embedded in MgO as a function of their size and concentration in the spectral range from 1.4 to 4.3 eV is presented. The nanoparticle layers were obtained by sputtering at different deposition temperatures. Transmission electr...

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Detalles Bibliográficos
Autores: Clavero, C., Cebollada, Alfonso, Armelles Reig, G., Huttel, Y., Arbiol i Cobos, Jordi, Peiró Martínez, Francisca, Cornet i Calveras, Albert
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2005
País:España
Institución:Universidad de Barcelona
Repositorio:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/10623
Acceso en línea:https://hdl.handle.net/2445/10623
Access Level:acceso abierto
Palabra clave:Nanopartícules
Propietats òptiques
Propietats magnètiques
Magnetic properties and materials
Optical properties
Condensed matter
Descripción
Sumario:A study of the magneto-optical (MO) spectral response of Co nanoparticles embedded in MgO as a function of their size and concentration in the spectral range from 1.4 to 4.3 eV is presented. The nanoparticle layers were obtained by sputtering at different deposition temperatures. Transmission electron microscopy measurements show that the nanoparticles have a complex structure which consists of a crystalline core having a hexagonal close-packed structure and an amorphous crust. Using an effective-medium approximation we have obtained the MO constants of the Co nanoparticles. These MO constants are different from those of continuous Co layers and depend on the size of the crystalline core. We associate these changes with the size effect of the intraband contribution to the MO constants, related to a reduction of the relaxation time of the electrons into the nanoparticles.