Experiments using Force Detected Nuclear Magnetic Resonance*

We describe experiments using force detected nuclear magnetic resonance (NMR). We have developed a helium-3 system for high sensitivity measurements. An initial room temperature scan on (NH$_{4}$)$_{2}$SO$_{4}$ demonstrated 1-D resolution of 10 $\mu$m; a spin nutation experiment determined the value of the rotating magnetic field to be 13 gauss, and a spin echo was observed with a full width half maximum of 8 $\mu$s. At 77 K we obtained the first force detected boron NMR signal in a 30 $\mu$m powder sample of the superconductor MgB$_{2}$. Our measurements yielded a force of 10$^{-13}$ N with $B_{1}$ = 63 gauss. Further studies are underway to map the spin lattice relaxation with respect to temperature to elucidate the pairing symmetry of MgB$_{2}$ as well as effects due to its two nearly independent electronic bands. In addition we describe the construction of a compact room temperature probe and a variable temperature probe for dynamical imaging experiments.