W. Wernsdorfer et al., HIGH-SENSITIVITY MAGNETIZATION MEASUREMENTS OF NANOSCALE COBALT CLUSTERS, Journal of applied physics, 78(12), 1995, pp. 7192-7195
Presented is a novel high sensitivity magnetometer allowing us to meas
ure the magnetization reversal of about 10(4) mu(beta) corresponding t
o a sensitivity of about 10(-16) emu. The detector is a niobium micro-
bridge DC superconducting quantum interference device (SQUID), fabrica
ted using electron-beam lithography. It is operational in the temperat
ure range of 0-7 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 re
versal takes place by small avalanches. (C) 1995 American Institute of
Physics.