Branching ratio and angular distribution of ejected electrons from Eu 4f ⁷ 6p _1/2 n d auto-ionizing states

Abstract

The branching ratios of ions and the angular distributions of electrons ejected from the Eu 4f 7 6p 1/2 nd auto-ionizing states are investigated with the velocity-map-imaging technique. To populate the above auto-ionizing states, the relevant bound Rydberg states have to be detected first. Two new bound Rydberg states are identified in the region between 41150 cm −1 and 44580 cm −1 , from which auto-ionization spectra of the Eu 4f 7 6p 1/2 nd states are observed with isolated core excitation method. With all preparations above, the branching ratios from the above auto-ionizing states to different final ionic states and the angular distributions of electrons ejected from these processes are measured systematically. Energy dependence of branching ratios and anisotropy parameters within the auto-ionization spectra are carefully analyzed, followed by a qualitative interpretation.

Synthetic Method for Preparing High-Performance Europium-Doped Up-Conversion Ceramic Material Precursor

“…In addition, when the reaction concentration is less than 5%, the intensity of the absorption peak gradually increases as the reaction concentration decreases, but the position of the absorption peak does not change. Combining with the morphology image, it can be suggested that the increase of the intensity of the powder absorption peak is due to the improvement of the agglomeration, then more light absorption into grain leads to the increase of the absorption intensity [31,32]. Europium whose maximum excitation peak intensity is located at 464nm is mainly corresponds to the 7 F0→ 5 D2 (464nm) transition of Eu 3+ ion [33][34][35].…”