低场固体核磁共振魔角旋转探头关键部件的研制OA

High-field solid-state nuclear magnetic resonance(NMR)technology boasts high sensitivity and multi-nucleus detection capability.However,when studying paramagnetic materials like lithium-ion batteries,the strong paramagnetism of transition metal ions(such as Mn3+,Fe3+,etc.)leads to issues like magnetic field inhomogeneity,spectral line broadening,signal attenuation,and inability to perform magic-angle spinning(MAS)at high magnetic fields.Under low-field conditions,the magnetic field distortion induced by paramagnetic effects is significantly reduced,offering a potentia l solution to these problems.This paper presents a theoretical analysis of the advantages of low-field environments for studying paramagnetic substances.A low-field solid-state MAS probe for a 0.5 T Halbach magnet was developed.Furthermore,a complete low-field solid-state MAS spectrometer was constructed.In experiments,7Li NMR signals of various paramagnetic samples were acquired at a spinning speed of 12 kHz,verifying the feasibility of the self-developed low-field solid-state MAS technology for paramagnetic samples.This approach addresses the problems of overlapping spin sidebands and MAS failure at high fields,providing a new pathway for NMR research on paramagnetic materials.