Electronic Spectra and Crystal Field Analysis of Energy Levels of Ho³⁺ in HoF₆³⁻

Abstract

The electronic absorption spectra of single crystals of Cs(2)NaHoF(6) have been recorded in the spectral region between 4700 and 42000 cm(-1) at temperatures down to 10 K. The structure in the (5)I(8) → (5)I(J) (J = 7-4), (5)F(J) (J = 5-1), (5)S(2), (5)G(J) (J = 4-6), (3)K(J) (J = 7, 8) transitions has been analyzed and assigned. The emission spectra (5)S(2) → (5)I(J) (J = 6-8) and (5)G(4) → (5)I(J) (J = 5-7), (5)F(5) have also been recorded at 10 K for crystals of Cs(2)NaHoF(6) and partly also for samples of Cs(2)NaHoF(6):Yb(3+). The spectra comprise magnetic dipole zero phonon lines and electric dipole allowed one-phonon vibronic sidebands. From the detailed interpretation of the emission and absorption spectra, aided by a clear understanding of the vibrational behavior of the HoF(6)(3-) moiety and by magnetic dipole intensity calculations, a data set of 59 energy levels spanning 17 multiplet terms was derived. Crystal field calculations were then performed using a 4f(10) basis, as well as including the configuration interaction with a p-electron configuration. The latter calculation, which employed 14 parameters, gave better agreement with experiment and the mean deviation was 13.5 cm(-1). A comparison with the energy level fittings for Cs(2)NaHoCl(6) has been included. The crystal field parameters for the fluoro- and chloro-systems followed empirically predicted ratios.

Energy transfer from Bi3+ to Ho3+ triggers brilliant single green light emission in LaNbTiO6:Ho3+, Bi3+ phosphors

“…8,9 Ho 3+ possesses a wealth of energy levels and, consequently, has many luminescent states due to the complexity of the 4f 10 energy level system. 10 Malinowski et al pointed out that Ho 3+ systems have been investigated for application in infrared lasers for remote sensing and medical purposes. 11 Extensive investigations of the optical spectra of Ho 3+ have been carried out for M 3 Al 5 O 12 :Ho 3+ (M ¼ Y, Lu), 12 MLiF 4 :Ho 3+ (M ¼ Gd, Y, Lu), 13 MBi(XO 4 ):Ho 3+ (M ¼ Li, Na; X ¼ W, Mo).…”