Deuteron NMR lineshape computations for tunnelling ND<sub>4</sub><sup>+</sup> ions. I. First-order quadrupolar interactions
J S Blicharski; Z T Lalowicz; W Sobol; J S Blicharski; Inst. of Phys., Jagiellonian Univ., Krakow, Poland; Z T Lalowicz; Inst. of Phys., Jagiellonian Univ., Krakow, Poland; W Sobol; Inst. of Phys., Jagiellonian Univ., Krakow, Poland
Журнал:
Journal of Physics C: Solid State Physics
Дата:
1978-10-28
Аннотация:
Deuteron NMR lineshapes are computed for the ND<sub>4</sub><sup>+</sup> ion, taking into account dipolar and first-order quadrupolar interactions. Expressions for tunnelling-Hamiltonian matrix elements are given as linear combinations of seven overlap integrals related to the symmetry rotations of a tetrahedron. Examples of theoretical lineshapes are presented, exhibiting their sensitivity to tunnelling motions. Tunnelling effects for ND<sub>4</sub><sup>+</sup> are discussed and compared with related features for NH<sub>4</sub><sup>+</sup>. From an analysis of experimental lineshapes for ND<sub>4</sub>PF<sub>6</sub> and (ND<sub>4</sub>)<sub>2</sub>PtCl<sub>6</sub> at 1.6K, tunnelling frequencies of 1.6 MHz and 3.4 MHz respectively, are deduced. In these cases, large volumes of tunnelling splittings suppressed effectively second-order effects in the quadrupolar interaction.
716.9Кб