High sensitivity magnetization measurements of nanoscale cobalt clusters

W. Wernsdorfer (1) , Klaus Hasselbach (2) , A. Benoît (3) , B. Barbara (1) , D. Mailly (4) , J. Tuaillon (5) , J. Perez (5) , V. Dupuis (5) , J P Dupin (5) , G. Guiraud (5) , A Perex (5)

1 LLN - Laboratoire Louis Néel
2 CRTBT - Centre de Recherches sur les Très Basses Températures
3 IPNL - Institut de Physique Nucléaire de Lyon
4 LPN - Laboratoire de photonique et de nanostructures
5 DPM - Département de Physique des Matériaux

Presented is a novel high sensitivity magnetometer allowing us to measure the magnetization reversal of about IO4 pB corresponding to a sensitivity of about IO-r6 emu. The detector is a niobium micro-bridge DC superconducting quantum interference device (SQUID), fabricated using electron-beam lithography. It is operational in the temperature range of O-7 K. Furthermore, we present a method to deposit on the SQUID loop a small number of Co clusters of about 2-5 nm in diameter. The first results obtained on these samples show that there is still a ferromagnetic coupling between the clusters and the magnetization reversal takes place by small avalanches

Domaines: Matière Condensée [cond-mat]; Systèmes mésoscopiques et effet Hall quantique [cond-mat.mes-hall]

W. Wernsdorfer, Klaus Hasselbach, A. Benoît, B. Barbara, D. Mailly, et al.. High sensitivity magnetization measurements of nanoscale cobalt clusters. Journal of Applied Physics, 1995, 78 (12), pp.7192. ⟨10.1063/1.360429⟩. ⟨hal-01660030⟩