Bc. Stipe et al., Magnetic dissipation and fluctuations in individual nanomagnets measured by ultrasensitive cantilever magnetometry, PHYS REV L, 86(13), 2001, pp. 2874-2877
Cantilever magnetometry with moment resolution better than 10(4) mu (B) was
used to study individual nanomagnets. By using the fluctuation-dissipation
theorem to interpret measurements of field-induced cantilever damping, the
low frequency spectral density of magnetic fluctuations could be determine
d with resolution better than 1 mu (B) Hz(-1/2). Cobalt nanowires exhibited
significant magnetic dissipation and the associated magnetic fluctuations
were found to have 1/f frequency dependence. In individual submicron rare-e
arth alloy magnets, the dissipation/fluctuation was very small and not dist
inguishable from that of a bare silicon cantilever.