6533b85ffe1ef96bd12c1b2e
RESEARCH PRODUCT
Phase transition kinetics and reorientational dynamics of the plastic crystal meta-carborane studied by deuteron NMR
Herbert ZimmermannRoland BöhmerRoland BöhmerM. WinterlichM. Winterlichsubject
ChemistryRelaxation (NMR)Spin–lattice relaxationThermodynamicsCondensed Matter Physics530Electronic Optical and Magnetic MaterialsNMR spectra databaseMagnetizationCrystallographyCondensed Matter::Materials SciencePhase (matter)Materials ChemistryCeramics and CompositesOrthorhombic crystal systemCondensed Matter::Strongly Correlated ElectronsPlastic crystalMonoclinic crystal systemdescription
Meta-carborane shows an orientationally disordered, orthorhombic phase which transforms into an ordered monoclinic phase near 170 K and into a quasi-isotropic cubic phase near 280 K. From deuteron magnetization measurements both transitions are found to exhibit a thermal hysteresis and slow transformation kinetics. Furthermore, solid-echo NMR spectra and spin-lattice relaxation times are reported. These results indicate that in the orthorhombic phase the meta-carborane molecules perform a strongly anisotropic motion which is characterized by a temperature dependent amplitude.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2002-09-01 |