Enhancing MQMAS of low-γ nuclei by using a high B1 field balanced probe circuit

Crystal structure and proton conductivity of BaSn0.6Sc0.4O3−δ: insights from neutron powder diffraction and solid-state NMR spectroscopy

“…High field 45 Sc NMR experiments were performed at 19.6 T on a ultra-narrow bore Bruker DRX 830 MHz spectrometer at the National High Magnetic Field Laboratory, Tallahassee, Florida, USA using a home-built 1.8 mm single channel probe 22 tuned to 202.44 MHz. All samples were packed inside 1.8 mm rotors, spun at a spinning frequency ν r of 33.333 kHz, and short recycle delays of 0.2 s allowing full relaxation of the 45 Sc spins were used for the 1D spectra.…”

NMR spectroscopy up to 35.2 T using a series-connected hybrid magnet

“…The high field achievable at the SCH also narrows the line width along the direct dimension and provides an increase in the signal-to-noise ratio. The 3.2 mm MAS probe is capable of delivering 17 O rf fields as high as 100 kHz, which is critical to maximizing the efficiency of the multiple-quantum experiments [37]. …”

Recent Advances in Solid-State 25Mg NMR Spectroscopy

“…9,18 The condition n 1 (n q is satisfied for most usual probes, since the RF strength n 1 is typically well below n q value for a low-g nucleus such as 25 Mg. In the cases where more RF power is required, as it is typically the case of MQMAS and related experiments, the use of probes especially designed to attain high RF power levels and appropriate tuning at the low 25 Mg NMR frequency has been reported. 37,[42][43][44] Typical commercial probes used for MAS experiments are equipped with rotors having diameters in the range 2.5-7mm, which allows spinning speeds up to 45kHz. This value is sufficient in many cases for attaining the maximum possible narrowing of the second-order quadrupolar broadened CT in 25 Mg NMR spectra recorded at strong magnetic Δf d 0 Figure 3 Definition of the parameters d 0 (shift of the most intense peak) and Df (total breadth), in the 25 fields.…”

“…Some related work recently published involved the design of an electrically balanced probe capable of generating a high RF field strength to enhance the sensitivity of 25 Mg MQMAS NMR experiments in Mg/Al layered double hydroxides (LDHs). 44 1.5. Development of 25 Mg solid-state NMR The historical development of 25 Mg NMR is interesting in that there have been sporadic, almost one off attempts, which were then followed by more concerted streams of work as the quality of the data gradually improved, until the present day position of well-reproduced lineshapes across a wide range of compounds, has been achieved.…”