Vibronic Transitions of Eu^<3+> Ions in CaWO_4 and Other Tungstates

概要

論文の詳細を見る
Absorption and excitation spectra associated with the 4f-4f transitions of Eu^<3+> ions in CaWO_4:Eu, Na, NaEu(WO_4)_2 and KEu(WO_4)_2 were studied at low temperatures. Vibronic transitions are observed as bands with fine structure composed of sharp lines. The observed vibronic spectra were compared with the κ=0 phonon spectra of CaWO_4. Fairly good agreement is found between the both spectra, and the existence of a distinct gap in the spectra is noted. The intensity of the vibronic transition associated with ^7F_0⇾^5D_1 transition is weaker by one order of magnitude than those associated with ^7F_0⇾^5D_0 and ^5D_2 transitions. These results are well interpreted by use of Judd and Ofelt's theory. Namely, the ^7F_0⇾^5D_2 and ^5D_2 vibronic transitions are allowed by the first-order electric-dipole, while the ^7F_0⇾^5D_1 vibronic transition is only allowed by the second-order electric-dipole an first-order magnetic-dipole.
社団法人日本物理学会の論文
1971-09-05