A NEW GONIOMETER DESIGN FOR SINGLE-CRYSTAL NUCLEAR-MAGNETIC-RESONANCESPECTROSCOPY

A new goniometer for single-crystal nuclear magnetic resonance (NMR) s pectroscopy has been constructed and built into a multinuclear X-H-1 d ouble-tuned probe for cross-polarization and/or H-1 decoupling. Improv ements in the ease of mounting/remounting the crystal on the three rot ational axes and in the accuracy of the stepwise rotation about these axes have been achieved compared to the usual cube goniometer. A simil ar 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 thre e orthogonal axes, all perpendicular to the magnetic field. The crysta l is glued onto a tenon that fits precisely into the dovetails of the NMR goniometer and also into a slightly modified x-ray diffraction gon iometer, thereby allowing a high-accuracy determination of the orienta tion for the tensorial NMR interactions with respect to the crystal fr ame. The performance of the goniometer is illustrated by single-crysta l Na-23 NMR spectra of NaNO3. (C) 1996 American Institute of Physics.