SATELLITE LINES DUE TO ION-PAIRS IN LUMINESCENCE SPECTRA OF Y2O2S - EU3+

In the luminescence spectra of the5D0→7F1 transition of Y2O2S:Eu3+, satellite lines separated from the main lines by several cm-1 were observed. Under the excitation by 365 mε radiation, the intensity of the main line increases linearly with the concentration of Eu3+, whereas that of the satellite lines increases as the 1.36 th power of the concentration. When Gd3+is codoped in Y2O2S:Eu3+keeping the concentration of Eu3+constant, the intensity of the satellite lines relative to the main line increases with the concentration of Gd3+. It is concluded that the satellite lines originate from the splitting and shift of the crystalline-field components resulting from a slight lattice distortion around a pair of Eu3+ions or that of an Eu3+ion and a Gd3+ion which occupy two nearest cation sites. © 1969, THE PHYSICAL SOCIETY OF JAPAN. All rights reserved.