The recent results on hydrothermal synthesis of mixed rare earth-alkali or ammonium fluorides were presented. The initial ratios of the starting materials, pH value and reaction temperature were the critical factors for obtaining the single-phase product. Four main types of complex rare earth fluorides, AREF4, A2REF5, ARE2F7 and ARE3F10 (A=Na+, K+, Rb+, NH4+), appeared in the primary hydrothermal reactions. The correlation between cation sizes and the formation of mixed rare earth fluorides under mild hydro...
The spectra of RE-doped YPO4 （RE=Ce3＋, Pr3＋ or Nd3＋） have been measured. The spectroscopic and decay kinetics properties of pure host YPO4 were also studied at 8 K and 300 K, which indicated the host had taken part in the luminescent processes of activators. Under the excitation over the bandgap of the host, the electron could relax to the activators. Through the comparison of spectra and decay time, Nd3＋ doped YPO4 had better scinillation properties than Ce3＋ or Pr3＋ inYPO4.
