Infrared Absorption and Luminescence Spectra of Fe 2+ in Cubic ZnS: Role of the Jahn-Teller Coupling
Infrared Absorption and Luminescence Spectra of Fe 2+ in Cubic ZnS: Role of the Jahn-Teller Coupling
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立方 ZnS 中 Fe 2 的红外吸收和发光光谱：Jahn-Teller 耦合的作用
DOI：
10.1103/physrevb.4.777
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发表时间：
1971
期刊：
影响因子：
--
通讯作者：
G. Slack
中科院分区：
文献类型：
--
作者：
F. Ham;G. Slack
对立方ZnS中Fe 2+的E5 → T25吸收光谱提出了一种新的解释.结果表明，某些吸收峰，缺乏对应的发光，不能解释，如前所述，作为两个和三个声子边带的零声子跃迁，也不能归因于晶体场电子跃迁或简单的未移动的单声子边带。一个Jahn-Teller耦合内的T2 - 5水平，弱于自旋-轨道耦合，被证明是能够不仅部分淬火的T2 - 5自旋-轨道分裂，但也转移相关的一个声子水平的方式所需的帐户所观察到的光谱。这种动态Jahn-Teller效应，涉及同时耦合到一个低频模式（100 cm-1）和一个高频模式（100 cm-1），提出了解释的数据，在ZnS中的Fe 2+在耦合到TA和TO和/或LO声子的ZnS晶格。这种解释的声子耦合被证明是一致的时刻分析的光吸收和发光光谱的加宽使用的方法的亨利，Schnatterly，和Slichter。讨论了该模型与CdTe、MgAl 2 O 4、ZnSe、ZnTe、CdS、GaP和GaAs中Fe 2+光谱中相似特征的关系。它还表明，该模型提供了深入了解晶格声子和本地化模式之间的关系，占主导地位的强耦合系统中的Jahn-Teller耦合，它表明为什么集群模型的Jahn-Teller离子和它的最近的邻居往往很好地为这样的系统。
A revised interpretation of the E 5→ T 2 5 optical absorption spectrum of Fe 2+ in cubic ZnS is proposed. It is shown that certain absorption peaks, lacking a counterpart in the luminescence, cannot be interpreted, as previously done, as two-and three-phonon sidebands of the zero-phonon transitions, and also cannot be attributed to crystal-field electronic transitions or to simple unshifted one-phonon sidebands. A Jahn-Teller coupling within the T 2 5 level, weaker than the spin-orbit coupling, is shown to be capable not only of partially quenching the T 2 5 spin-orbit splitting but also of shifting the associated one-phonon levels in the manner required to account for the observed spectra. Such a dynamic Jahn-Teller effect, involving simultaneous coupling to a low-frequency mode (∼ 100 cm− 1) and a higher-frequency mode (∼ 300 cm− 1), is proposed to account for the data for Fe 2+ in ZnS in terms of coupling to the TA and TO and/or LO phonons of the ZnS lattice. This interpretation of the phonon coupling is shown to be consistent with a moment analysis of the broadening of the optical absorption and luminescence spectra using the methods of Henry, Schnatterly, and Slichter. The relation of this model to similar features in the spectrum of Fe 2+ in CdTe, Mg Al 2 O 4, ZnSe, ZnTe, CdS, GaP, and GaAs is discussed. It is also shown that this model provides insights into the relationship between lattice phonons and the localized modes that dominate the Jahn-Teller coupling in strongly coupled systems, and that it shows why the cluster model for the Jahn-Teller ion and its nearest neighbors often works well for such systems.