Spin-Lattice Relaxation of Three-Spin System through Intermolecular Dipole-Dipole Interaction
Spin-lattice relaxation process of the three-spin group (like CH3 or NH3) in solids has been studied for many years, while NMR relaxation experiments have turned out to be a powerful tool in the analysis of the molecular dynamics of such a system. In most of the cases a quantum aspects of those kinds of molecular reorientations have been considered. Tunneling, which is influenced both by intra- and intermolecular interactions, reflects the molecular environment of a given group 1). However, the classical description of the reorientation in the high-temperature range is also of some importance, particularly in the case when three-spin group plays an important role in the crystal lattice phase transition 2,3).