%0 Journal Article
%A González Herrera, Elvira María
%A Montero, M. I.
%A Cebollada, F.
%A De Julián Fernández, C
%A Vicent López, José Luis
%A González, J. M.
%T Magnetic properties of Ni nanoparticles dispersed in silica prepared by high-energy ball milling
%D 1998
%@ 0295-5075
%U https://hdl.handle.net/20.500.14352/60180
%X 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.
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