Magnetic properties of Ni nanoparticles dispersed in silica prepared by high-energy ball milling

We analyze the magnetic properties of mechanically ground nanosized Ni particles dispersed in a SiO_2 matrix. Our magnetic characterization of the as-milled samples show the occurrence of two blocking processes and that of non-monotonic milling time evolutions of the magnetic-order temperature, the...

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Detalles Bibliográficos
Autores: González Herrera, Elvira María, Montero, M. I., Cebollada, F., De Julián Fernández, C, Vicent López, José Luis, González, J. M.
Tipo de recurso: artículo
Fecha de publicación:1998
País:España
Institución:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/60180
Acceso en línea:https://hdl.handle.net/20.500.14352/60180
Access Level:acceso abierto
Palabra clave:538.9
Metal-films
Física de materiales
Física del estado sólido
2211 Física del Estado Sólido
Descripción
Sumario:We analyze the magnetic properties of mechanically ground nanosized Ni particles dispersed in a SiO_2 matrix. Our magnetic characterization of the as-milled samples show the occurrence of two blocking processes and that of non-monotonic milling time evolutions of the magnetic-order temperature, the high-field magnetization and the saturation coercivity. The measured coercivities exhibit giant values and a uniaxial- type temperature dependence. Thermal treatment carried out in the as-prepared samples result in a remarkable coercivity reduction and in an increase of the high-field magnetization. We conclude, on the basis of the consideration of a core (pure Ni) and shell (Ni-Si inhomogeneous alloy) particle structure, that the magnetoelastic anisotropy plays the dominant role in determining the magnetic properties of our particles.