Abstract. Radio-frequency (rf) field inhomogeneity is a common
problem in NMR which leads to non-ideal rotations of spins in parts of the sample. Often, a physical volume restriction of the sample is used to reduce
the effects of rf-field inhomogeneity, especially in solid-state NMR where spacers are inserted to reduce the sample volume to the centre of the coil.
We show that band-selective pulses in the spin-lock frame can be used to
apply B1-field selective inversions to spins that experience selected
parts of the rf-field distribution. Any frequency band-selective pulse can
be used for this purpose, but we chose the family of I-BURP pulses (Geen and Freeman, 1991) for the measurements demonstrated here. As an example, we show that the implementation of such pulses improves homonuclear frequency-switched
Lee–Goldburg decoupling in solid-state NMR.