A new goniometer design for single-crystal nuclear magnetic resonance spectroscopy

A new goniometer for single-crystal nuclear magnetic resonance (NMR) spectroscopy has been constructed and built into a multinuclear X-H-1 double-tuned probe for cross-polarization and/or H-1 decoupling. Improvements in the ease of mounting/remounting the crystal on the three rotational axes and in the accuracy of the stepwise rotation about these axes have been achieved compared to the usual cube goniometer. A similar improvement is achieved for the determination of the orientation of the crystal relative to the goniometer frame. The NMR goniometer has three dovetail mortises that enable rotation of the crystal about three orthogonal axes, all perpendicular to the magnetic field. The crystal is glued onto a tenon that fits precisely into the dovetails of the NMR goniometer and also into a slightly modified x-ray diffraction goniometer, thereby allowing a high-accuracy determination of the orientation for the tensorial NMR interactions with respect to the crystal frame. The performance of the goniometer is illustrated by single-crystal Na-23 NMR spectra of NaNO3. (C) 1996 American Institute of Physics.