22 research outputs found
Spatial characterization of the magnetic field profile of a probe tip used in magnetic resonance force microscopy
We have developed the experimental approach to characterize spatial
distribution of the magnetic field produced by cantilever tips used in magnetic
resonance force microscopy (MRFM). We performed MRFM measurements on a well
characterized diphenyl-picrylhydrazyl (DPPH) film and mapped the 3D field
profile produced by a Nd2Fe14B probe tip. Using our technique field profiles of
arbitrarily shaped probe magnets can be imaged.Comment: 10 pages, 5 figure
Localized ferromagnetic resonance force microscopy in permalloy-cobalt films
We report Ferromagnetic Resonance Force Microscopy (FMRFM) experiments on a
justaposed continuous films of permalloy and cobalt. Our studies demonstrate
the capability of FMRFM to perform local spectroscopy of different
ferromagnetic materials. Theoretical analysis of the uniform resonance mode
near the edge of the film agrees quantitatively with experimental data. Our
experiments demonstrate the micron scale lateral resolution in determining
local magnetic properties in continuous ferromagnetic samples.Comment: 7 pages, 3 figure
Ferromagnetic resonance force microscopy on a thin permalloy film
Ferromagnetic Resonance Force Microscopy (FMRFM) offers a means of performing
local ferromagnetic resonance. We have studied the evolution of the FMRFM force
spectra in a continuous 50 nm thick permalloy film as a function of probe-film
distance and performed numerical simulations of the intensity of the FMRFM
probe-film interaction force, accounting for the presence of the localized
strongly nonuniform magnetic field of the FMRFM probe magnet. Excellent
agreement between the experimental data and the simulation results provides
insight into the mechanism of FMR mode excitation in an FMRFM experiment.Comment: 9 pages, 2 figure
Manipulating Spins by Cantilever Synchronized Frequency Modulation: A Variable Resolution Magnetic Resonance Force Microscope
We report a new spin manipulation protocol for periodically reversing the
sample magnetization for Magnetic Resonance Force Microscopy. The protocol
modulates the microwave excitation frequency synchronously with the position of
the oscillating detection cantilever, thus allowing manipulation of the spin
magnetization independent of both magnetic field gradient strength and
cantilever response time. This allows continuous variation of the detected
sample volume and is effective regardless of spin relaxation rate. This
enhanced flexibility improves the utility of MRFM as a generally applicable
imaging and characterization tool.Comment: 3 pages, 3 figure