title: Electron spin relaxation near a micron-size ferromagnet.
abstract: Magnetic resonance force microscopy was used to study the behavior of small ensembles of unpaired electron spins in silica near a micrometer-size ferromagnetic tip. Using a cantilever-driven spin manipulation protocol and a magnetic field gradient greater than 10(5) T/m, signals from as few as 100 net spins within a 20 nm thick resonant slice could be studied. A sixfold increase in the spin-lattice relaxation rate was found within 800 nm of the ferromagnet, while no effect due to silica surface proximity was detected. The results are interpreted in terms of Larmor-frequency magnetic field fluctuations emanating from the ferromagnet.
authors.affiliation: IBM Research Division, Almaden Research Center, 650 Harry Road, San Jose, California 95120, USA.
authors.forename: B C
authors.initials: BC
authors.lastname: Stipe
authors.forename: H J
authors.initials: HJ
authors.lastname: Mamin
authors.forename: C S
authors.initials: CS
authors.lastname: Yannoni
authors.forename: T D
authors.initials: TD
authors.lastname: Stowe
authors.forename: T W
authors.initials: TW
authors.lastname: Kenny
authors.forename: D
authors.initials: D
authors.lastname: Rugar