Rotational States of NH+4in Dilute Solution in Alkali Halide Lattices. I. Inelastic Neutron Scattering Studies

摘要: Rotational tunneling and torsional energy states of the NH + 4 ion in several alkali halide lattices (KCl, KBr, KI, RbI CsI) have been characterized range 0< e <42 meV. The most detailed spectra are obtained for specimen KBr/NH Br (0.5 mole%) at low energies ( <2 meV) temperature region 1.5< T <30 K. results consistent with a model tetrahedron an octahedral field. An investigation ratios intensities neutron loss gain peaks (0.5%) leads to conclusion that conversion between nuclear spin symmetry species occurs characteristic time hours. This is general agreement findings NMR measurements on same described following paper. Moreover, heat capacity display non-lattice contribution which much less than would correspond rapid conversion. On other hand, in...