Magnetic dissipation and fluctuations in individual nanomagnets measured by ultrasensitive cantilever magnetometry.
Cantilever magnetometry with moment resolution better than 10(4)micro(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 determined with resolution better than 1micro(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-earth alloy magnets, the dissipation/fluctuation was very small and not distinguishable from that of a bare silicon cantilever.
Stipe
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BC
IBM Research Division, Almaden Research Center, 650 Harry Road, San Jose, CA 95120-6099, USA.
Mamin
H J
HJ
Stowe
T D
TD
Kenny
T W
TW
Rugar
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D