Small crystals and small coils in variable-temperature single-crystal NMR

Time savings by a factor of between 20 and 30 in the acquisition of multinu clear single-crystal (SC) NMR spectra have been obtained for submillimeter- size (0.01 to 0.03 mm(3)) single crystals when compared to recent results f or P-31 and Rb-87 SC NMR, This gain in sensitivity is achieved by optimizin g the filling factor using the smallest possible rf coil (2.0 mm inner diam eter) for the specific SC probe design. Furthermore, this small coil is par ticularly useful for variable-temperature SC NMR studies. A probe design fo r such studies is presented and demonstrated experimentally. (C) 2000 Acade mic Press.