Structure and transport properties in an N,N-substituted pyrrolidinium tetrafluoroborate plastic crystal system

The structure and transport of N-propyl-N-methylpyrrolidinium tetrafluoroborate (P13BF4) has been investigated over a wide temperature range in consequence to exhibiting properties suitable for potential solid-state superionic electrolyte applications. Prior to melting, the organic salt, P13BF4, transforms into a plastic crystal phase. Intrinsic conductivity in this solid, phase 1 (45-65 degreesC), is comparable to that in the melt (similar to10(-3) S cm(-1)). Ionic motion and transport properties were investigated by H-1 and B-11 nuclear magnetic resonance (NMR) spectroscopy. Pressure-induced plastic flow in this system may accommodate volume changes in device application and to this extent, X-ray diffraction (XRD) has been used. Scanning electron microscopy (SEM) revealed complex surface morphology and lattice imperfections associated with the strong orientational disorder of the plastic state. (C) 2002 Elsevier Science B.V. All rights reserved.