The preparation of rare earth phosphate fine particles in an emulsion liquid membrane systemElectronic supplementary information (ESI) available: SEM images of phosphate particles prepared in the homogeneous system, and SEM images of La phosphate particles prepared via the ELM system, following calcination for 2 h at 573 and 1373 K. See http://www.rsc.org/suppdata/jm/b1/b105743j/

Abstract

Phosphate particles of the selected rare earth metals have been prepared, using an emulsion liquid membrane [ELM, water-in-oil-in-water (W/O/W) emulsion] system, consisting of Span 83 (sorbitan sesquioleate) as surfactant and EHPNA (2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester) as extractant (cation carrier). The rare earth ions are extracted from the external water phase of the ELM system and are stripped into the internal water phase, containing phosphoric acid solution, to form the corresponding rare earth phosphate particles. The morphology and size of the particles are well-controlled by using the ELM system, and submicrometer-sized spherical phosphate particles are obtained, while micron-sized and irregular-shaped phosphate particles are obtained in homogeneous aqueous solutions. The resulting submicrometer-sized spherical particles were characterized by scanning electron microscopy (SEM), powder X-ray diffraction (XRD), and thermal analysis (TG-DTA). The characterization of La-based particles revealed that the fine particles obtained were of hexagonal structure, but their crystalline structure was changed to a monoclinic structure by calcination at 1373 K. Composite LaPO 4 :Ce 31 ,Tb 31 phosphor particles were then prepared by transporting La 31 , Ce 31 , and Tb 31 ions simultaneously, with the resulting particles showing good photoluminescence at 545 nm. In the ELM system, the size of the particles is able to be controlled in the range of 0.28 to 0.65 mm by changing the concentration of Span 83, whereas that in the homogeneous system is about 0.7 mm.

Luminescence properties of Sm3+ doped YPO4: Effect of solvent, heat-treatment, Ca2+/W6+-co-doping and its hyperthermia application

“…Tetragonal phase is observed for pure YPO 4 sample (JCPDF 11-0254). When 2 at.% Sm 3+ is co-doped in YPO 4 , additional peaks related to hexagonal phase appear, but their intensities are very weak. On increasing Sm 3+ concentration, peak intensities related to hexagonal phase increase, whereas peak intensities corresponding to the tetragonal phase decrease.…”

“…• C. The (2-10 at.%) Sm 3+ doped YPO 4 shows the mixture of phases of tetragonal and hexagonal, which transform to the tetragonal phase above 800…”

“…There are also not any reports regarding the luminescence recovery of these materials which, has been quenched by the presence of a luminescence quencher such as OH − ions. In this study, we have prepared Sm 3+ (2, 5, 7, 10 and 20 mol%) doped YPO 4 , in aqueous condition using a co-precipitation technique. The correlation among phase transformation, content of water molecules, and luminescence intensity of Sm 3+ has been studied using X-ray diffraction (XRD), infrared spectroscopy (IR), thermo gravimetry (TG), transmission electron microscopy (TEM), and luminescence techniques.…”

“…The correlation among phase transformation, content of water molecules, and luminescence intensity of Sm 3+ has been studied using X-ray diffraction (XRD), infrared spectroscopy (IR), thermo gravimetry (TG), transmission electron microscopy (TEM), and luminescence techniques. Core shell nanoparticles like CaWO 4 …”

“…[1][2][3] Lanthanide phosphates as a material find extensive application as laser, ceramic, sensor, phosphor, heat-resistant materials, field-effect transistors and also in optoelectronics, medical and biological labels, solar cells and light sources. [4][5][6][7][8][9][10][11] Lanthanide phosphate-based compositions are used as host matrices in fluorescent lamps and color TV monitors due to their strong vacuum ultra-violet (VUV) absorption which is attributed to their (PO 4 ) tetrahedral. [12][13][14] Among the different kinds of rare-earth orthophosphates, yttrium orthophosphate has been shown to be an efficient host lattice for rare earth activator ions, which have become a research focus because of their important role in the field of light display systems, lasers, and optoelectronic devices.…”