Micro-SQUID technique for studying the temperature dependence of switching fields of single nanoparticles

Christophe Thirion (1) , Wolfgang Wernsdorfer (1) , M. Jamet (2) , V. Dupuis (2) , P. Melinon (2) , A. Perez (2) , D. Mailly

1 LLN - Laboratoire Louis Néel
2 LPMCN - Laboratoire de Physique de la Matière Condensée et Nanostructures

An improved micro-SQUID technique is presented allowing us to measure the temperature dependence of the magnetisation switching fields of single nanoparticles well above the critical superconducting temperature of the SQUID. Our first measurements on 3 nm cobalt nanoparticle embedded in a niobium matrix are compared to the Neel Brown model describing the magnetisation reversal by thermal activation over a single anisotropy barrier.

Domaines: Systèmes mésoscopiques et effet Hall quantique [cond-mat.mes-hall]; Science des matériaux [cond-mat.mtrl-sci]

Christophe Thirion, Wolfgang Wernsdorfer, M. Jamet, V. Dupuis, P. Melinon, et al.. Micro-SQUID technique for studying the temperature dependence of switching fields of single nanoparticles. Journal of Magnetism and Magnetic Materials, 2002, 242-45, pp.993-995. ⟨10.1016/S0304-8853(01)01130-1⟩. ⟨hal-00022924⟩