Magnetic circular dichroism and absorption spectra of I-5(8) -> F-5(5) transition in HoAl3(BO3)(4) and HoFe3(BO3)(4) single crystals

Malakhovskii, A. V.; Sokolov, V. V.; Gudim, I. A.; Rautskii, M. V. Source: PHYSICS LETTERS A, 383 (16):1960-1966; 10.1016/j.physleta.2019.03.016 JUN 6 2019

Comparative study of magnetic circular dichroism (MCD) and absorption spectra of HoAl₃(BO₃)₄ and HoFe₃(BO₃)₄ single crystals in the region of ${}^{5}I_{8} \to {}^{5}F_{5}$ transition of the Ho³⁺ ion was carried out. Absorption spectra were decomposed into the Lorentz shape components and intensities of transitions were obtained. Unusually strong vibronic transitions were observed in HoAl₃(BO₃)₄, but were not observed in HoFe₃(BO₃)₄ that testified to the strong non diagonal vibronic interaction in HoAl₃(BO₃)₄. The MCD spectra were analyzed in approximation of the $| J, \pm M_{J} 〉$ wave functions of the free atom and using concept of the crystal quantum number. Peculiarity of application of this concept to ions with integer moments was revealed and modification of the concept was suggested. With the help of the MCD spectra, the Zeeman splitting of some transitions was found. In particular, the Landé factor $g_{C} \approx 2$ of the ground state of the Ho³⁺ ion in HoAl₃(BO₃)₄ in the trigonal axis direction was determined. It appeared to be five times less than that in HoFe₃(BO₃)₄ also found with the help of the MCD.