Magnetic circular dichroism (MCD) and absorption spectra of multiferroic HoFe3(BO3)4 of 5I8 → 5F2 and 5F3 f–f transitions are measured at T = 90 K. The absorption spectra are expanded into Lorentzian components, and the transition intensities are obtained. The Zeeman splitting of some transitions is determined using the MCD and absorption spectra. The MCD spectra and Zeeman splitting are theoretically analyzed in the free-atom |J, ±MJ〉 wave function approximation by using the concept of a crystalline quantum number. An inconsistency is revealed when this concept is applied to ions with an integer moment, and a modification of the concept is proposed. Anomalously intense vibronic repetitions of electronic transitions from excited sublevels of the ground multiplet are found.

中文翻译：

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HoFe3(BO3)4单晶中f-f跃迁5I8→5F2和5F3的磁性圆二色性和吸收光谱

5I8 → 5F2 和 5F3 f-f 跃迁的多铁性 HoFe3(BO3)4 的磁圆二色性 (MCD) 和吸收光谱在 T = 90 K 下测量。吸收光谱扩展为洛伦兹分量，并获得跃迁强度。某些跃迁的塞曼分裂是使用 MCD 和吸收光谱确定的。利用晶体量子数的概念，在自由原子|J,±MJ>波函数近似中对MCD谱和塞曼分裂进行了理论分析。当将此概念应用于具有整数矩的离子时，会发现不一致，并提出了对该概念的修改。发现了来自地面多重态的激发亚能级的电子跃迁的异常强烈的振动重复。