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本文研究了立方晶体中６Ｓ（３ｄ５）离子的零场分裂，其理论基础是扩展晶体场模型──该模型用两个参量（即ζｔｅ和ζｔｔ）描述自旋－轨道相互作用。本文的研究表明，晶体场与自旋－轨道耦合的共同作用将产生零场分裂；除这个熟知的机理外，自旋－轨道耦合将单独贡献于零场分裂。这一新机理的形成，本质上是共价性作用，它导致ζｔｅ与ζｔｔ的值不相同，最终作用于零场分裂，为了进一步揭示这一新机理，我们详细分析了各种贡献于零场分裂的耦合过程。结果发现：不同电子组态之间的耦合过程对零场分裂有一正的贡献，其值正比于ζｔｅ；而其它过程的贡献则为负，且正比于ζｔｅζｔｔ，因而，零场分裂的总值就决定于这两部分贡献之相对大小，而ζｔｅ与ζｔｔ之间的细微差别将严重影响零场分裂的大小。应用这一新理论，本文成功地解释了一些过去的理论不能解的实验数据，如，对Ｍｎ２＋：ＺｎＦｅ，用过去的理论得α＝０．３×１０－４ｃｍ－１，比实验值（２９．６×１０－４ｃｍ－１）小两个数量级；用本文提出的新理论，则得α＝２４．８×１０－４ｃｍ－１，与实验一致。
In this paper, the zero-field splitting of 6S (3d5) ions in cubic crystals is studied. The theoretical basis of this model is to extend the crystal field model, which describes the spin-orbit interaction with two parameters (ζte and ζtt). Our work shows that the interaction of the crystal field with spin-orbit coupling will produce zero-field splitting. In addition to this well-known mechanism, spin-orbit coupling will separately contribute to zero-field splitting. The formation of this new mechanism is essentially a covalent effect, which leads to the different values of ζte and ζtt, which finally act on the zero-field splitting. To further reveal this new mechanism, we analyze in detail the contributions of various contributions to zero field Split coupling process. The results show that the coupling process between different electronic configurations has a positive contribution to the zero-field splitting, the value of which is proportional to ζte, while the contribution of other processes is negative and proportional to ζteζtt. Therefore, the total value of zero-field splitting Depending on the relative contribution of these two contributions, the nuances of ζte and ζtt will seriously affect the magnitude of zero-field splitting. Applying this new theory, we successfully explain some experimental data that can not be solved theoretically in the past. For example, for Mn2 +: ZnFe, α = 0.3 × 10-4cm-1, .6 × 10-4cm-1) is two orders of magnitude smaller. With the new theory proposed in this paper, α = 24.8 × 10-4cm-1, which is consistent with the experiment.