Characterization of an MRFM probe in the SPAM geometry

This talk will describe a new MRFM probe built by the author that uses in the SPAM geometry, operates in vacuum at 4 K, up to 9 T, has 3D sample stage motion, uses Cornell cantilevers with spring constants of 0.1 mN/m with 7 um diameter nickel spheres mounted on the cantilever, and spring based vibration isolation that results in Brownian motion limited behavior at 4 K. The talk will describe the probe's Brownian motion and frequency deviations noise behavior vs. operating conditions, the cantilever's frequency and Q dependence vs. background magnetic field, power density spectra of cantilever fluctuations both far from and near a gold coated GaAs surface, the importance of cantilever control for noise abatement, and NMR line shapes of Ga69.