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arXiv · 1009.2609

Superspin glass aging behavior in textured and nontextured frozen ferrofluid

Sawako Nakamae·Emmanuelle Dubois·Vincent Dupuis·Denis L'Hôte·Régine Perzynski·Eric Vincent·Caroline Thibierge
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Abstract

The effect of magnetic anisotropy-axis alignment of individual nanoparticles on the collective aging behavior in the superspin glass state of a frozen ferrofluid has been investigated. The ferrofluid studied here consists of maghemite nanoparticles (\gamma-Fe2O3, mean diameter = 8.6 nm) dispersed in glycerin at a volume fraction of ~15%. The low temperature aging behavior has been explored through 'zero-field cooled magnetization' (ZFCM) relaxation measurements using SQUID magnetometry. The ZFCM response functions were found to scale with effective age of the system in both textured and non-textured superspin glass states, but with markedly different scaling exponents, \mu. The value of {\mu} was found to shift from ~0.9 in non-textured case to ~ 0.6 in the textured case, despite the identical cooling protocol used in both experiments.

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Sawako Nakamae, Emmanuelle Dubois, Vincent Dupuis, Denis L'Hôte, Régine Perzynski, Eric Vincent, Caroline Thibierge. 2010-09-14. Superspin glass aging behavior in textured and nontextured frozen ferrofluid. https://doi.org/10.1063/1.3366615

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