Effect of Linear Jahn-Teller Coupling on Paramagnetic Resonance in a 2 E State
Effect of Linear Jahn-Teller Coupling on Paramagnetic Resonance in a 2 E State
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线性 Jahn-Teller 耦合对 2 E 态顺磁共振的影响
DOI：
10.1103/physrev.166.307
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发表时间：
1968
期刊：
影响因子：
--
通讯作者：
F. Ham
中科院分区：
文献类型：
--
作者：
F. Ham
从仅考虑线性耦合的弱Jahn-Teller耦合极限出发，发展了动态Jahn-Teller效应对E2态电子顺磁共振谱影响的理论。通过在自旋哈密顿量中引入适当的约化因子，可以简单地表示振动基态的EPR谱的主要变化，该哈密顿量描述了磁场、应变或超精细相互作用对电子E2态的分裂。这些约化因子影响自旋哈密顿量的各向异性部分，但不影响各向同性部分；它们被Jahn-Teller耦合从整体上减弱；它们类似于早些时候在三重态理论中引入的约化因子。用该理论讨论了Höchli关于CaF2和SrF2中Sc2+的数据和Coffman关于Cu2+在MgO中的数据。虽然后一种情况与中等强度的线性Jahn-Teller耦合或隧道模型相一致，但本理论适用于CaF2和SrF2中的Sc2+，表明在这些情况下Jahn-Teller耦合很弱。
The theory of the effect of a dynamic Jahn-Teller effect on the electron-paramagnetic-resonance spectrum of a E 2 state is developed from the limit of weak Jahn-Teller coupling taking account only of linear coupling. The principal changes produced in the EPR spectrum of the vibronic ground state may be represented simply by introducing appropriate reduction factors into the spin Hamiltonian which describes the splitting of the electronic E 2 state by a magnetic field, strain, or hyperfine interaction. These reduction factors affect the anisotropic part of the spin Hamiltonian but not the isotropic part; they are diminished from unity by the Jahn-Teller coupling; and they are analogous to the reduction factors introduced earlier in the theory of a triplet state. The theory is used to discuss Höchli's data for Sc 2+ in Ca F 2 and Sr F 2 and Coffman's data for Cu 2+ in MgO. While the latter case is consistent with either a moderately strong linear Jahn-Teller coupling or with the tunneling model, the present theory applied to Sc 2+ in Ca F 2 and Sr F 2 indicates that in these cases the Jahn-Teller coupling is quite weak.