Size and anisotropy determination by ferromagnetic resonance in dispersed magnetic nanoparticles systems

DE BIASI EMILIO; RAMOS CARLOS; ZYSLER ROBERTO

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS

Año: 2003 vol. 262 p. 235 - 241

0304-8853

We present results for the FMR line shape modelling of non-interacting magnetic nanoparticle systems. We compare the results of the Smit and Beljers formalism and the usual linear-model, where the effective anisotropy field, Heff A ; in the superparamagnetic regime is considered as a perturbation to the Zeeman interaction and added to the applied field, H: superparamagnetic regime is considered as a perturbation to the Zeeman interaction and added to the applied field, H: A ; in the superparamagnetic regime is considered as a perturbation to the Zeeman interaction and added to the applied field, H: superparamagnetic regime is considered as a perturbation to the Zeeman interaction and added to the applied field, H: Heff A ; in the superparamagnetic regime is considered as a perturbation to the Zeeman interaction and added to the applied field, H: superparamagnetic regime is considered as a perturbation to the Zeeman interaction and added to the applied field, H: ; in the superparamagnetic regime is considered as a perturbation to the Zeeman interaction and added to the applied field, H:H: While the difference between these approaches is negligible for small Heff A (high temperature regime), it becomes more pronounced when Heff A EH: We show how these results influence the determination of the parameters characterizing an array of random particles. array of random particles. A EH: We show how these results influence the determination of the parameters characterizing an array of random particles. array of random particles. pronounced when Heff A EH: We show how these results influence the determination of the parameters characterizing an array of random particles. array of random particles. A EH: We show how these results influence the determination of the parameters characterizing an array of random particles. array of random particles. A (high temperature regime), it becomes more pronounced when Heff A EH: We show how these results influence the determination of the parameters characterizing an array of random particles. array of random particles. A EH: We show how these results influence the determination of the parameters characterizing an array of random particles. array of random particles. pronounced when Heff A EH: We show how these results influence the determination of the parameters characterizing an array of random particles. array of random particles. A EH: We show how these results influence the determination of the parameters characterizing an array of random particles. array of random particles. Heff A (high temperature regime), it becomes more pronounced when Heff A EH: We show how these results influence the determination of the parameters characterizing an array of random particles. array of random particles. A EH: We show how these results influence the determination of the parameters characterizing an array of random particles. array of random particles. pronounced when Heff A EH: We show how these results influence the determination of the parameters characterizing an array of random particles. array of random particles. A EH: We show how these results influence the determination of the parameters characterizing an array of random particles. array of random particles. (high temperature regime), it becomes more pronounced when Heff A EH: We show how these results influence the determination of the parameters characterizing an array of random particles. array of random particles. A EH: We show how these results influence the determination of the parameters characterizing an array of random particles. array of random particles. Heff A EH: We show how these results influence the determination of the parameters characterizing an array of random particles. array of random particles. EH: We show how these results influence the determination of the parameters characterizing an array of random particles.