Quadrupolar spin-lattice relaxation in solids

Alternating spin chain compound AgVOAsO4 probed by As75 NMR

“…The 75 As spin-lattice relaxation time T 1 was measured at the field corresponding to the highest peak position. The recovery of the longitudinal magnetization at different temperatures after a group of saturation pulses was fitted by the following double-exponential function 19 …”

Effects of jump dynamics on solid state nuclear magnetic resonance line shapes and spin relaxation times

“…As noted in Table 1, facilities are included for simulating non-spinning powder line shapes, QCPMG multiple echo trains, and MAS/OMAS spectra for spin 3/2, 5/2, 7/2 and 9/2 governed by a combination of second order quadrupole coupling and anisotropic chemical shift interactions. EXPRESS does not include routines for jump-dynamic contributions to spin lattice relaxation of high spin quadrupoles, although such routines would be easy to implement, because in most cases the dominant relaxation mechanism involves spin-phonon coupling rather than single-particle jumps [76,53].…”

Quadrupolar NMR to Investigate Dynamics in Solid Materials

“…For a spin I nucleus, the spin-lattice relaxation can be described by up to 2I distinct relaxation times arising from the 2I rate equations that define the transition probabilities between the various energy levels [37]. For I > ½ nuclei experiencing a non-zero quadrupolar interaction, and assuming that the first-order quadrupolar interaction is the dominant relaxation mechanism, all Δm = 2 transitions and Δm = 1 satellite transitions will e ach contribute with t ransition probabilities aW 2 and bW 1 respectively, where a and b are factors specific to the two levels involved in the transition as well as the direction of t he transition [37,38]. W hen the magnetic relaxation mechanism is dominant, relaxation is mediated only by Δm = 1 transitions, and the central and satellite transitions will each contribute transition probabilities dependent on a single rate process W. In both cases, the relaxation is typically multi-exponential.…”