A Theory of the Cooperative Jahn-Teller Effect –Crystal Distortions in Cu1-xNixCr2O4 and Fe1-xNixCr2O4–
A Theory of the Cooperative Jahn-Teller Effect –Crystal Distortions in Cu1-xNixCr2O4 and Fe1-xNixCr2O4–
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协同 Jahn-Teller 效应理论 – Cu1-xNixCr2O4 和 Fe1-xNixCr2O4 中的晶体畸变 –
DOI：
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发表时间：
1972
期刊：
影响因子：
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通讯作者：
J. Kanamori
中科院分区：
文献类型：
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作者：
M. Kataoka;J. Kanamori
提出了一种合作Jahn-Teller效应理论，用于讨论Cu1-xNixCr2O4和Fe1-xNixCr2O4混合铬酸盐中的自发晶体扭曲。只考虑了静态的Jahn-Teller效应。该理论将具有简并轨道能级的每个离子的自能与导致合作现象的那些能量分开；前者的能量代表了持续在立方相中的局部扭曲的影响。该理论还区分了Jahn-Teller耦合与体应变和离子的相对位移的贡献。该理论成功地解释了混合铬铁矿相图的各种特征，如转变温度的浓度依赖性、畸变量的大小、正交相的出现等。文中还讨论了弹性模量值的温度依赖性，指出它将给出更多的信息。
A theory of the cooperative Jahn-Teller effect is developed for the purpose of discussing the spontaneous crystal distortions in mixed chromites, Cu 1- x Ni x Cr 2 O 4 and Fe 1- x Ni x Cr 2 O 4 . The static Jahn-Teller effect only is taken into account. The theory separates the self-energy of each ion having a degenerate orbital level from those energies which contribute to the cooperative phenomenon; the former energy represents the effect of a local distortion which persists in the cubic phase. The theory also distinguishes between the contributions of the Jahn-Teller coupling with the bulk strains and with relative displacements of ions. The theory explains successfully various features of the phase diagrams of the mixed chromites such as the concentration dependences of the transition temperatures and the magnitudes of the distortions, the appearance of an orthorhombic phase, etc. The temperature dependence of elastic moduli is also discussed to point out that it will yield additional informations, pa...