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arXiv · 0912.0483

Role of dipolar interactions in a system of Ni nanoparticles studied by magnetic susceptibility measurements

S. H. Masunaga·R. F. Jardim·P. F. P. Fichtner·J. Rivas
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Abstract

The role of dipolar interactions among Ni nanoparticles (NP) embedded in an amorphous SiO2/C matrix with different concentrations has been studied performing ac magnetic susceptibility Chi_ac measurements. For very diluted samples, with Ni concentrations < 4 wt % Ni or very weak dipolar interactions, the data are well described by the Neel-Arrhenius law. Increasing Ni concentration to values up to 12.8 wt % Ni results in changes in the Neel-Arrhenius behavior, the dipolar interactions become important, and need to be considered to describe the magnetic response of the NPs system. We have found no evidence of a spin-glasslike behavior in our Ni NP systems even when dipolar interactions are clearly present.

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S. H. Masunaga, R. F. Jardim, P. F. P. Fichtner, J. Rivas. 2009-12-02. Role of dipolar interactions in a system of Ni nanoparticles studied by magnetic susceptibility measurements. https://doi.org/10.1103/physrevb.80.184428

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