Low-power broadband NMR of paramagnetic materials at 111 kHz-MAS

Abstract

International audienceFor the first time we report better performance of a low-power single-sideband-selective (S3AP) pulse than a high-power (ω1 > ωR) broadband pulse under ultrafast MAS conditions, and that these pulses are easily implemented. We show that the inefficiency of the high-power pulse comes from the inability of ultrafast MAS probes to deliver sufficiently large RF fields. For spins with large anisotropies (Ω > ωR), we extend the S3AP pulse to irradiate multiple sidebands simultaneously and show that this can improve both the pulse efficiency and the accuracy of the observed spinning sideband pattern