We present first study of magnetic circular dichroism (MCD) spectra of Ho ion in local symmetry, which it has in fluorite NaHoF. Optical absorption and MCD spectra were studied in this single crystal in the region of → , , and transitions in the temperature range 3.6–––90 K. It was revealed, that number of transitions observed in the MCD and absorption spectra coincides with the number of transitions only from the doublet state to singlet excited states. The - type transitions are not active in MCD, but they are not observed in the absorption spectra either. Paramagnetic magneto-optical activities (MOA) of the absorption bands and their temperature dependences were measured and interpreted with the help of the theory based on the nature of transitions allowance. The MCD spectra were also analyzed in approximation of the wave functions of the free atom. It was shown in particular, that the lowest initial state of the transitions observed at > 10 K had = 7, but this is not the lowest state of the holmium ion in the crystal. A little lower there is a quasi-doublet with = 8 and, accordingly, with a higher magneto-optical activity of transitions from it. However, the intensity of transitions from this state is low.

中文翻译：

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Na0.4Ho0.6F2.2单晶磁圆二色性和ff跃迁吸收光谱的性质

我们首次研究了萤石 NaHoF 中具有局域对称性的 Ho 离子的磁圆二色性 (MCD) 光谱。研究了该单晶在 3.6–––90 K 温度范围内 → 、 和跃迁的光吸收和 MCD 光谱。结果表明，在 MCD 和吸收光谱中观察到的跃迁数与仅从双重态到单重激发态的跃迁。 - 型跃迁在 MCD 中不活跃，但在吸收光谱中也没有观察到。借助基于跃迁余量性质的理论，测量并解释了吸收带的顺磁磁光活动（MOA）及其温度依赖性。还对自由原子波函数的近似值进行了 MCD 光谱分析。特别表明，在 > 10 K 时观察到的跃迁的最低初始态 = 7，但这并不是晶体中钬离子的最低态。稍低一点的是= 8的准双峰，因此，从它的跃迁具有更高的磁光活性。然而，从这种状态转变的强度很低。