Crystals of Eu3+-doped material were tested in a diamond-anvil cell, at high pressures and temperatures, in order to produce a non-equilibrium distribution of charge-compensating interstitial fluorides. The re-equilibration dynamics were then studied by annealing the treated sample at normal pressures. The re-equilibration covered a temperature range of 80, and corresponded to an 0.34eV range in the diffusional activation energy. Spectroscopic techniques were used to study major sites, as well as several previously unreported minor defect clusters. It was noted that changes in the main sites were related to changes in the minor clusters.

L.R.Olsen, A.O.Wright, J.C.Wright: Physical Review B, 1996, 53[21], 14135-44