Imaging the spatial distribution of radiofrequency field, sample and temperature in MAS NMR rotor

(a) Picture of a 1.3 mm rotor including spacers at top and bottom positions to display the restricted volume. Colored squares represent the different positions of an insert of 1 × 1.2 mm used to record 1H spectra in a gradient B0 field. (b) 1H spectra of the insert in B0 gradient generated along the rotor axis. (c) FT of a 2D nutation experiment under B0 gradient showing the correlation of rf-field with frequency.224