title: Spin-locking mechanism of spin I = 3/2 quadrupolar nuclei undergo magic angle spinning.
abstract: The spin-locking mechanism of the spin I = 3/2 quadrupolar nuclei under magic angle spinning (MAS) has been theoretically and experimentally investigated, and the criterion of adiabatic passage around zero-crossings of the quadrupole splitting was inferred from the time-dependent Shrödinger equation in this article. The theory, numerical simulations, and experiments conducted in this work all indicated that second-order quadrupole interaction and off-resonance play important roles in the spin-locking of the quadrupolar nuclei, and they were responsible for the great loss of the spin-locking signals. The spin-locking for a spin I = 3/2 nucleus might be achieved by minimizing the effect of the second-order quadrupole interaction by using a radio frequency (RF) offset. This offset was realized by setting the RF to the opposite position of the isotropic second-order quadrupolar shift of single quantum coherences.
authors.affiliation: Laboratory of Nuclear Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, The Chinese Academy of Sciences.
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
authors.forename: F
authors.initials: F
authors.lastname: Deng
authors.forename: J
authors.initials: J
authors.lastname: Qiu
authors.forename: C
authors.initials: C
authors.lastname: Ye
mesh_terms: D009682:Magnetic Resonance Spectroscopy