A5RE4X[TO4]4 crystal growth and photoluminescence. Fluoride flux synthesis of sodium and potassium rare earth silicate oxyfluorides†
Abstract
Crystals of Na5RE4F[SiO4]4 (RE = Pr, Nd, Sm–Tm) and K5Pr4F[SiO4]4 were grown using a fluoride flux synthetic technique. All compositions crystallize in the tetragonal space group I with lattice parameter ranges of a = 11.5094(2)–12.3745(2) Å and c = 5.37000(10)–5.5011(2) Å. Antiferromagnetic ordering is observed for Na5RE4F[SiO4]4 (RE = Tb, Dy), second harmonic generation for Na5RE4F[SiO4]4 (RE = Pr, Sm–Ho), and intense optical properties and fluorescence quantum yield for Na5RE4F[SiO4]4 (RE = Eu, Gd, Tb). The crystal structures and physical property measurements are discussed.