A new experimental procedure for characterizing quantum effects in small magnetic particle systems
Service de Physique de l'Etat Condensé, CEA Saclay 91191 Gif-sur-Yvette Cedex, France
2 Laboratoire PMC, CNRS URA D1254, Ecole Polytechnique - 91128 Palaiseau, France
3 Laboratoire de Physico-Chimie Inorganique, case courrier 63, UPMC, 4 place Jussieu, 75252 Paris, France
Accepted: 10 February 1997
A new experimental procedure is discussed, which aims at separating thermal from quantum behavior independently of the energy barrier distribution in small particle systems. Magnetization relaxation data measured between 60 mK and 5 K on a sample of nanoparticles is presented. The comparison between experimental data and numerical calculations shows a clear departure from a standard thermal dynamics scenario, a result which was not obvious without using the new procedure presented here.
PACS: 75.45.+j – Macroscopic quantum phenomena in magnetic systems / 75.50.Tt – Fine-particle systems / 75.60.Lr – Magnetic aftereffects
© EDP Sciences, 1997