Magnetic Relaxation in Big Magnetic Molecules
Magnetic Relaxation in Big Magnetic Molecules
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大磁性分子中的磁弛豫
DOI：
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发表时间：
1994
期刊：
影响因子：
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通讯作者：
A. Rettori
中科院分区：
文献类型：
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作者：
J. Villain;F. Hartman;R. Sessoli;A. Rettori
计算了磁性大分子的磁化驰豫时间。假设各向同性交换占主导地位，得到固定的自旋模数S(在感兴趣的情况下等于20)。Asz2形式的微扰是由自旋-轨道耦合产生的，并产生了将Sz的正值和负值分开的能垒As2。自旋-声子相互作用用二阶微扰理论处理。得到了Arrhenius定律中指数前因子的一个上限值，这与很大的实验值是一致的。
The relaxation time of the magnetization of a big magnetic molecule is evaluated. Isotropic exchange is assumed to be dominant, resulting in a fixed spin modulus s (equal to 20 in the case of interest). A perturbation of the form ASz2 results from spin-orbit coupling and produces an energy barrier As2 which separates positive and negative values of Sz. Spin-phonon interactions are treated by second-order perturbation theory. An upper limit of the pre-exponential factor in the Arrhenius law is obtained, which is consistent with the very large experimental value.