Absorption, Fluorescence, and Energy Levels of the Dysprosium Ion*

The absorption and fluorescence spectra of DyCl3·6H2O have been observed at 4.2°K and 77°K. This makes an analysis of the low-lying levels possible including their Stark splitting. The strong lines have been interpreted as transitions between the 6H, 6P, and 6F multiplets. The Zeeman effect gives a splitting of s1=6.73 if the acute bisectrix is parallel to the field.