Synthesis and Crystal Structure Characterization of Silicate Apatite Sr₂Y₈(SiO₄)₆O₂

Abstract

Pure Sr2Y8(SiO4)6O2 powders were obtained after a solid‐state reaction at 1400 °C for 6 h using the nanosized Y2O3, commercial SrCO3, and silica gel. The nanosized Y2O3 powder was synthesized by a precipitation method using Y(NO3)3 and NH4HCO3, followed by a heat treatment. The crystal structure of Sr2Y8(SiO4)6O2 was characterized by powder X‐ray diffraction, Rietveld refinement, and high‐resolution transmission electron microscopy. Results show that Sr2Y8(SiO4)6O2 has a typical apatite‐type structure AI4AII6(BO4)6X2 in the P63/m space group. The lattice parameters are a=9.3884(6) Å and c=6.8657(4) Å. There are two special sites, AI (4f) and AII (6h), in the apatite structure. The AII sites are fully occupied by Y, while the AI sites are randomly filled by Y and Sr atoms. The crystallographic data obtained from Sr2Y8(SiO4)6O2 and other silicate oxyapatites are compared and summarized.

Study of the cation distributions in Eu doped Sr2Y8(SiO4)6O2 by X-ray diffraction and photoluminescent spectra

“…2a and their identical shapes demonstrates the high purities of all these samples. The small deviations between the present refinement data and the previous study [21] may be due to different synthesis methods. Fig.…”

“…Sr 2 Y 8 (SiO 4 ) 6 O 2 apatite has been used as host materials in the ultrafast laser system [9][10][11], and it possesses P6 3 /m symmetry with Sr 2 + and Y 3 + randomly distributed in the 4f sites and Y 3 + fully occupied the 6h sites [21]. After sol-gel synthesis, the distribution of Eu 3 + dopant between the two cationic sites in Sr 2 Y 8 (SiO 4 ) 6 O 2 apatite was analyzed through the combination of X-ray diffraction, the Rietveld refinement and the photoluminescent spectra.…”

“…Bruker AXS, Karlsruhe, Germany). The crystal structure of Sr 2 Y 8 (SiO 4 ) 6 O 2 had been studied previously [21] and the structure model of it was used in the present study. The parameters were refined in the following sequence: background by using Chebychev function, cell parameters, crystal size, atom positions, global thermal parameters, and site occupancies.…”

Photoluminescence characteristics of high thermal stable fluorosilicate apatite Ba2Y3(SiO4)3F:Sm3+ orange-red emitting phosphor

“…The M(I) (Wycoff 4f site) and M(II) (Wycoff 6h site) positions are two distinct crystallographic sites that accommodate alkali, alkaline-earth, or rare-earth atoms, the B site is occupied by phosphorous, vanadium, silicon, boron, or germanium, and X is the anion site for halogen, hydroxyl, or oxygen. Apatite structure is a compositionally flexible network and can be widely modified by substitutions on cationic and/or anionic sites [16][17][18]. Apatite compounds have been confirmed to be efficient luminescence materials for cathodoluminescence and white LEDs (w-LEDs) [19][20][21][22][23][24][25].…”

Versatile luminescence of Eu^2+,3+-activated fluorosilicate apatites M_2Y_3[SiO_4]_3F (M = Sr, Ba) suitable for white light emitting diodes

“…Its structure is hexagonal belonging to space group P6 3 /m, with a single tetrahedral site (TO 4 ) and two non-equivalent sites for the ten metallic ions (M). Apatite structure is a compositionally flexible network and can be widely modified by substitutions on cationic and/or anionic sites [2]. Apatite compounds have been confirmed to be efficient luminescence materials for white LEDs (W-LEDs) [3].…”