Sb3+ and Mn2+ Activated Calcium Halophosphate Phosphors from Flux-Grown Apatites

Abstract

reduce the amounts of other impurities also if the oxychloride recrystallization process is used. It is evident that commercial sources of zirconia, if used in the preparation of other zirconium compounds, will introduce the same undesirable impurities if luminescence phenomena involving other activator ions are being considered, for example, the rare earths. It is possible that these impurities may not have as pronounced a detrimental effect in such compounds as they do in ZrO2 alone.It is probable that Ti 4+ replaces Zr 4+ in monoclinic ZrO2 substitutionally rather than interstitially. The usual coordination of Ti 4+ in oxide compounds is octahedral. In monoclinic ZrO2, however, the coordination of Ti 4+ is likely the same unusual asymmetric sevenfold coordination discussed previously. This highly asymmetric environment may account for the strong emission which can be developed.The slow build-up of steady-state luminescence and the long persistence of irradiated samples at room temperature is probably related to the filling and emptying of a relatively large number of traps which were shown to exist. Several strong g10w peaks were detected above liquid nitrogen temperature. One of the peaks occurs between 0 ~ and 20~ ABSTRACTThe crystallization of calcium chloro-and chloro-fluoroapatites from calcium halide fluxes was studied as a function of composition and heating schedules. Activation of Ca5 (PO4)3F0.9C10.1 was investigated by varying phosphor stoichiometry and firing methods. The results indicate that flux-grown apatites are slightly deficient in PO43-and that for a particle size of predominantly 50-100~, 72-hr firing at 1150~ causes only limited incorporation of Sb 3+, Cd 2+, and additional PO43-. The incorporation of Mn 2+ is more extensive and may be nearly uniform. The rate of migration of Mn and Sb toward the interior of the crystals increases with increasing PO48-[as (NH4)2HPO4] added prior to activation; however, maximum emission occurs at a calculated over-all metal/phosphorus ratio of exactly 5/3. High output of heterogeneously emitting crystals suggests that quantum efficiency is independent of activator concentration. ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 130.102.42.98 Downloaded on 2015-03-13 to IP ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 130.102.42.98 Downloaded on 2015-03-13 to IP Vol. 113, No. 2 CALCIUM HALOPHOSPHATE PHOSPHORS ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 130.102.42.98 Downloaded on 2015-03-13 to IP ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 130.102.42.98 Downloaded on 2015-03-13 to IP

Correlation between the emission properties of Sn²⁺ center and the chemical composition of ZnO–P₂O₅ glasses

“…The valence state of Sn in the Sn:xZP glasses was examined, which could be the most important information in understanding our results. Figure 1 shows the 119 Sn Mössbauer spectra of Sn:60ZP and 1SnO68ZnO31P 2 2+ from these non-symmetric peaks can be calculated, no significant differences between the two spectra are observed owing to the low S/N ratio. Based on these results, we assume that the thermal, optical, and emission properties of these glasses (discussed below) depend on the local coordination state of Sn 2+ species, although a clear difference in the isomer shift of Sn 2+ is not observed.…”

“…Figure 3(a) shows the optical absorption spectra of Sn:xZP glasses containing various amounts of ZnO. As the absorption bands originate from the sp transition of Sn 2+ center, the values of (h¯¡) 2 are plotted as a function of photon energy. Here, h,¯, and ¡ are the Planck's constant, frequency of light, and optical absorption coefficient, respectively.…”

“…This is because the ns 2 -type center (n = 4) exhibits s-p parity allowed transition and these species, such as Sn 2+ 4+ have also been reported to exhibit photoluminescence (PL) properties characteristic of the ns 2 -type emission center in oxide glasses. 8),9) It is of particular importance to study the optical properties of such metastable species in amorphous materials such as random oxide networks, in order to understand their local environment.…”

“…8),9) It is of particular importance to study the optical properties of such metastable species in amorphous materials such as random oxide networks, in order to understand their local environment. Since the ns 2 type emission centers possess electrons in the outermost shell in the ground (ns 2 ) and excited states (ns 1 np 1 ), 1) the emission is strongly affected by the coordination field. Therefore, it is worthwhile to examine ns 2 center-doped oxide glasses for understanding the correlation between the luminescence property and the chemical composition of the glass.…”

Hydrothermal synthesis of one-dimensional hydroxyapatite particles using calcium sodium nitrilotriacetate as a calcium reservoir

“…Hydroxyapatite [Ca 10 (PO 4 ) 6 (OH) 2 , HAP] is a biomineral that makes up the bones and teeth of vertebrates. Because of biocompatibility, synthetic HAP can find applications such as production of artificial bones and dental implants.…”