Photoluminescent and Magnetic Properties of Lanthanide Containing Apatites: Na_xLn_10–x(SiO₄)₆O_2–yF_y, Ca_xLn_10–x(SiO₄)₆O_2–yF_y (Ln = Eu, Gd, and Sm), Gd_9.34(SiO₄)₆O₂, and K_1.32Pr_8.68(SiO₄)₆O_1.36F_0.64

Abstract

Single crystals of NaEu(9)(SiO(4))(6)O(2), Na(1.5)Eu(8.5)(SiO(4))(6)OF, Na(1.64)Gd(8.36)(SiO(4))(6)O(0.72)F(1.28), Gd(9.34)(SiO(4))(6)O(2), Ca(2.6)Eu(7.4)(SiO(4))(6)O(1.4)F(0.6), Ca(4.02)Sm(5.98)(SiO(4))(6)F(2), and K(1.32)Pr(8.68)(SiO(4))(6)O(1.36)F(0.64) and powders of NaEu(9)(SiO(4))(6)O(2), Na(1.5)Eu(8.5)(SiO(4))(6)OF, Eu(9.34)(SiO(4))(6)O(2), and Gd(9.34)(SiO(4))(6)O(2) were synthesized via flux growth in selected alkali-fluoride melts. All of the compounds adopt the apatite structure with space group P6(3)/m. Luminescence and magnetic data were collected on NaEu(9)(SiO(4))(6)O(2), Na(1.5)Eu(8.5)(SiO(4))(6)OF, Eu(9.34)(SiO(4))(6)O(2), and Gd(9.34)(SiO(4))(6)O(2). Luminescent data indicate that changing the cations and anions that surround the lanthanide site does not change the luminescent properties, making apatites versatile structures for optical materials.

A5RE4X[TO4]4crystal growth and photoluminescence. Hydroflux synthesis of sodium rare earth silicate hydroxides

“…11,19,23 Fluorescence quantum yields were measured on polycrystalline samples of Na 5 RE 4 IJOH)ijSiO 4 ] 4 (RE = Eu, Gd, Tb). Our Tb analogue has its maximum emission peak at 542 nm.…”

Flux Crystal Growth and Structure Determination of K5Y2FSi4O13

“…Rare earth containing silicates have been studied extensively for their magnetic and optical properties with solid state lighting fueling recent drives in silicate materials [1][2][3][4][5]. Fluoride flux crystal growth has been shown to be a good synthetic route for exploratory work in silicates due to the solubility of silica in fluorides, such as NaF and KF [1,[4][5][6][7].…”

“…Fluoride flux crystal growth has been shown to be a good synthetic route for exploratory work in silicates due to the solubility of silica in fluorides, such as NaF and KF [1,[4][5][6][7]. In this work, crystals of K 5 Y 2 FSi 4 O 13 were synthesized using a molten potassium fluoride flux.…”

Fluoride Flux Crystal Growth and Structure Determination of K5Sc2FSi4O13

“…Furthermore, some of these fluxes can act as ''reactive fluxes'' where one or more of the flux components are incorporated into the crystal products. For example, one method to obtain oxyfluoride single crystals, as described herein, is to use molten fluoride fluxes, which are known to act as reactive fluxes in many situations [1][2][3][4].…”

“…4). The K(1) ion occupies a site in the channel between the fluorine sites that runs down the b axis, the K(2) occupies a site in the channel between the Si(3) tetrahedra down the b axis, K(3) occupies a site in the channel between Si(1) and Si(2), almost in line with O(3) down the b axis, K(4) …”