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

Author(s)

Masunaga‚ SH ; Jardim‚ RF ; Fichtner‚ PFP ; Rivas‚ J.

• Document type: Journal article
• Source: Physical Review B; v. 80, n. 18, p. 184428, 2009.

Abstract

The role of dipolar interactions among Ni nanoparticles (NPs) embedded in an amorphous SiO(2)/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 Neacuteel-Arrhenius law. Increasing Ni concentration to values up to 12.8 wt % Ni results in changes in the Neacuteel-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. (AU)

• FAPESP's process: 05/53241-9 - Study of intergranular phenomena in ceramic materials
• Grantee: Reginaldo Muccillo
• Support Opportunities: Research Projects - Thematic Grants