Vector model of electron spin echo envelope modulation due to nuclear hyperfine and zeeman interactions
Vector model of electron spin echo envelope modulation due to nuclear hyperfine and zeeman interactions
复制标题
由于核超精细和塞曼相互作用而产生的电子自旋回波包络调制的矢量模型
DOI：
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
Y. Tsvetkov
中科院分区：
文献类型：
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作者：
A. Maryasov;M. Bowman;Y. Tsvetkov
有效自旋S =1/2的顺磁中心与非四极核相互作用的横向电子自旋磁化强度可以表示为围绕有效磁场方向旋进的核磁化强度矢量对的函数。这对矢量中的每一个矢量都垂直于两个有效场开始进动。对于核自旋I =1/2，自由感应衰减（FID）信号与矢量的标量积成比例。电子自旋回波（ESE）信号可以用两对磁化矢量来描述。ESE波形不等于两个背靠背FID信号，除非没有ESE包络调制。一个递归关系，它允许计算ESE信号的较大的核自旋在核四极相互作用的情况下。该关系可用于计算任意核自旋的ESE信号随核磁化矢量变化的时间过程。虽然这种形式主义允许定量计算的调制从核，它也提供了一个定性的手段，可视化的调制基于简单的磁化矢量。
The transverse electron spin magnetization of a paramagnetic center with effective spinS=1/2 interacting with nonquadrupolar nuclei may be presented as a function of pairs of nuclei magnetization vectors which precess around the effective magnetic field directions. Each vector of the pair starts its precession perpendicular to both effective fields. The free induction decay (FID) signal is proportional to the scalar product of the vectors for nuclear spinI=1/2. The electron spin echo (ESE) signal can be described with two pairs of magnetization vectors. The ESE shape is not equal to two back-to-back FID signals except in the absence of ESE envelope modulation. A recursion relation is obtained which allows calculation of ESE signals for larger nuclear spins in the absence of nuclear quadrupole interaction. This relation can be used to calculate the time course of the ESE signal for arbitrary nuclear spins as a function of the nuclear magnetization vectors. While this formalism allows quantitative calculation of modulation from nuclei, it also provides a qualitative means of visualizing the modulation based on simple magnetization vectors.