Abstract

I.R. emission and absorption of Pa⁴⁺ in thorium tetrahalide crystals due to transitions between ²F_7/2 ⇄ ²F_5/2 of 5 f¹ configuration have earlier been reported. In this paper, the visible and near U.V. spectra of Pa⁴⁺ in ThBr₄ are discussed. From the low temperature luminescence, absorption and excitation spectra it is concluded that 6d - 5f transitions are responsible for the observed spectra. Table I summarizes the spectral data recorded on a Jobin-Yvon HR 1000 spectrometer. Oriel-7240 monochromator in conjunction with a tungsten halogen continuum source was used to record the excitation spectra. The visible and near U.V.

© 1984 Optical Society of America