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

Autor:	Masunaga, S. H., Jardim, R. F., Fichtner, P. F. P., Rivas, J.
Rok vydání:	2009
Předmět:	Condensed Matter - Mesoscale and Nanoscale Physics Condensed Matter - Materials Science
Zdroj:	Physical Review B 80, 184428 (2009)
Druh dokumentu:	Working Paper
DOI:	10.1103/PhysRevB.80.184428
Popis:	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. Comment: 7 pages, 5 figures, 3 tables
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/0912.0483 Zobrazit plný text záznamu View this record from Arxiv