Micromechanical sensing of magnetic force was used to detect nuclear magnetic resonance with exceptional sensitivity and spatial resolution. With a 900 angstrom thick silicon nitride cantilever capable of detecting subfemtonewton forces, a single shot sensitivity of 1.6 x 10(13) protons was achieved for an ammonium nitrate sample mounted on the cantilever. A nearby millimeter-size iron particle produced a 600 tesla per meter magnetic field gradient, resulting in a spatial resolution of 2.6 micrometers in one dimension. These results suggest that magnetic force sensing is a viable approach for enhancing the sensitivity and spatial resolution of nuclear magnetic resonance microimaging.

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Advantages of superconducting quantum interference device-detected magnetic resonance over conventional high-frequency electron paramagnetic resonance for characterization of nanomagnetic materials

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A NMR technique for direct determination of internuclear distances in amorphous solids is described and illustrated with a measurement of the carbon–carbon bond length in acetic acid at −190 °C. The result, 1.488 °A, is sufficiently close to the x-ray value of 1.478 °A to confirm the effectiveness of the overall approach. The pulse sequence used, and the ensuing spectral analysis, ensure a very direct measurement of internuclear distances in amorphour solids.