Breakdown in the efficiency factor of the mixed Magic Sandwich Echo: A novel NMR probe for slow motions

An exact analytical solution for the evolution of a dipole–dipole interacting system under spherical diffusion in magnetic resonance experiments

“…(27), written by using bisection formulas, is formally identical to Eq. (7), except for a factor of 4 3 multiplying the phase. Seeing how the phase in our formula is calculated by multiplying the various poles x i and the time t,…”

“…To compare our relaxation function with a FID acquired from rotationally diffusing spin pairs, the ''spin exchange'' feature of SPINEVOLUTION has been employed. This approach was already used and described in [4]. Since SPINEVOLUTION is unable to reproduce a continuous, smooth diffusional motion of its ''crystallites'' (the base elements upon which the powder average is performed), the actual diffusion process has been mimed by discretizing the solid angle into four directions pointing at the corners of a regular tetrahedron from its center, and randomly cycling the spin pairs into these possible orientations at a constant frequency K given as a parameter.…”

“…Abragam [1] provides a function, known as the ''abragamian'', to describe the FID in systems dominated by dipolar interactions in the rigid lattice regime. On the other hand, in the presence of fast motion an exponential shape is often assumed, and linear combinations of the two are sometimes used to represent the shape in all the intermediate regimes [2][3][4].…”

Probing with Nuclear Magnetic Resonance echo decay and relaxation: A study on nitrile butadiene rubber

“…(1). First (Section 4.1) the temperature behaviour of the efficiency factor Z will be shortly addressed, by resorting to an approach [22] recently developed. Then (Section 4.2) the relaxation rates will be comprehensively analyzed, in terms of the effective distribution of the correlation frequencies and by taking into account the insights derived from the FID's and from the efficiency factors as well.…”

Proton NMR spin-diffusion studies of PS-PB block copolymers at low field: two- vs three-phase model and recalibration of spin-diffusion coefficients

“…The increase at higher temperatures is associated with the onset of motions related to the glass transition. 1,18 For both samples, these relative loss of signal of the rigid phase was corrected for all MSE-detected experiments.…”