INVESTIGATION OF CHARGE-TRANSFER O2--]LN3+ AND F--]LN3+ IN LAF3(LN3+, O2-) AND YF3(LN3+, O2-) SYSTEMS

Excitation spectra of the visible luminescence of Eu3+, Dy3+, Er3+ ions doped into two fluoride matrices, LaF3 and YF3, holding some traces of O2- ions were recorded in the UV and VUV range. Charge transfer bands O2- --> Ln3+ (Ln3+ = Eu3+, Dy3+, Er3+) and F- --> Eu3+ appear clearly on excitation spectra recorded at low temperature. Using the experimental data and Jorgensen's theoretical developments, it becomes possible to predict the energy of charge transfer O2- --> Ln3+ and F- --> Ln3+ for all the trivalent ions of the lanthanide series. The time-dependent theory was used to simulate the CT absorption profile.