72F1. 28, Gd9. 34 (SiO4) 6O2, Ca2. 6Eu7. 4 (SiO4) 6O1. 4F0. 6, Ca4. 02Sm5. 98 (SiO4)
6F2, and K1. 32Pr8. 68 (SiO4) 6O1. 36F0. 64 and powders of NaEu9 (SiO4) 6O2, Na1.
5Eu8. 5 (SiO4) 6OF, Eu9. 34 (SiO4) 6O2, and Gd9. 34 (SiO4) 6O2 were synthesized via flux
growth in selected alkali-fluoride melts. All of the compounds adopt the apatite structure with
space group P 63/m. Luminescence and magnetic data were collected on NaEu9 (SiO4) …