固态NMR中自旋Ⅰ=1体系的魔术回波序列

虽然组合脉冲固体回波大大地减轻了有限脉冲宽度的影响,但是它们并没有完全消除有限脉冲宽度带来的失真,而且产生另一种失真,即所谓的位相失真。本文分析了组合脉冲序列,将它用来构成魔术回波序列,这样就能消除位相失真。理论和实验的结果都证明,自旋I=1的组合脉冲魔术回波在线型的测量上优于组合脉冲固体回波序列,基本上解决了²D核核磁共振中有限脉冲宽度带来的难题。

MAGIC ECHO SEQUENCE IN SPIN-I SYSTEMS IN SOLID-STATE NMR

While the composite pulise solid echo sequences reduce the effects of finite pulse width greatly, they do not eliminate them completely, and they introduce a new type of distortion into the powder lineshape, that is, the phase error. The present paper analyzed the composite pulse, and used it to construct the Magic Echo Sequence for I=1 spin systems for compensating the phase error. The theory was confirmed by computer simulations and experimental results. It is clear that the performance of the composite pulse Magic Echo Sequence is superior to that of the composite pulse solid echo sequences, and essentially solved the problems due to finite pulse width effects for ²D-NMR spectroscopy.