Line Absorption Spectra of Rare Earth Ions in Crystals

摘要

Absorption spectra of the sulfate octahydrates of Er+++, Dy+++, Ho+++and Tm+++have been obtained at temperatures ranging from 14°K to 300°K. From the study of the variation in intensity of the absorption lines with temperature, energy levels have been found, in Er+++, at 19, 41 and 86 cm‐1above the normal state. Similar levels have been found in Dy+++at 22 and 57 cm‐1above the lowest. No such low energy states have been found in Ho+++and Tm+++.