Transparent ceramics of Holmium-doped yttria (Ho:Y2O3) were fabricated by Hot Isostatic Pressing at 1720 °C / 190 MPa in argon, and the effect of YF3 addition on their microstructure, optical, vibronic and infrared emission properties was studied. The fluorine addition improves the ceramic transparency, accelerates the grain growth and enhances the luminescence lifetimes of Ho3+ states responsible for emissions at 2 µm and 3 µm.
Delaunay et al. (Mon,) studied this question.