粉末样品自旋3/2四极核中心跃迁的高分辨核磁共振谱

本文利用脉冲对自旋3/2四极核中心跃迁激发的选择性,在粉末样品中用一个90°脉冲将电场梯度张量在空间某一取向的核自旋磁化矢量转到旋转坐标系中XY平面进行检测,从而得到与单晶样品类似的高分辨谱线,在理论上用密度算符公式作了分析,实验上用NaNO₂和Na₂SO₄粉末样品进行了验证。 关键词：

HIGH-RESOLUTION NMR SPECTROSCOPIC STUDY ON THE CENTRAL TRANSITION OF SPIN-3/2 QUADRUPOLAR NUCLEI IN POWDERS

We make use of the selectivity of pulse excitation in the central transition of spin-3/2 quadrupolar nuclei, and in powder sample, employ a 90°pulse to rotate the nuclear spin magnetization of certain spatial orientation of the electric-field-gradient tensor to the XY plane of the rotating frame for detection. Thus, high resolution spectrum similar to that obtained in a single crystal is acquired. The result is analyzed by density operator formula theoretically and confirmed by ²³Na spectra of NaNO₂ and Na₂SO₄ powders experimentally.