Tunable emission properties of tri-doped Ca_9LiY_(2/3)(PO_4)_7:Ce~(3+),Tb~(3+),Mn~(2+) phosphors with warm white emitting based on energy transfer

Tri-doped Ca_9 LiY_(2/3)(PO_4)_7:Ce~(3+),Tb~(3+),Mn~(2+)phosphors were prepared by a high-temperature solid state method.Under UV light excitation,Ca_9 LiY_(2/3)(PO_4)_7:Ce~(3+)samples exhibit a broad band ranging from 320 to 500 nm.At 77 K,the emission spectra of Ca_9 LiY_(2/3)(PO_4)7:Ce~(3+)samples present two obvious emission peaks,indicating that Ce~(3+)ions occupy two different kinds of lattice sites(Ca(1/2) and Ca(3)),As a good sensitizer for Tb~(3+),Ce~(3+)ions in Ca_9 LiY_(2/3)(PO_4)_7 lattice can effectively transfer part of energy to Tb~(3+),and the energy trans fer mechanism is determined to be dipole-dipole interaction.Consequently,the emitting color for Ce~(3+) and Tb~(3+) co-doped Ca_9 LiY_(2/3)(PO_4)_7 samples can be tuned from bluish violet to green.In order to further enlarge the emission gamut,Mn~(2+)ions as red emission components were added,forming tri-doped single-phase Ca_9 LiY_(2/3)(PO_4)_7:Ce~(3+),Tb~(3+),Mn~(2+)phosphors.The Ca_9 LiY_(2/3)(PO_4)_7:Ce~(3+),Tb~(3+),Mn~(2+)phosphors exhibit tunable emission properties through controlling the relative doping concentration of Ce~(3+),Tb~(3+)and Mn~(2+).Especially,Ca_9 LiY_(2/3)(PO_4)_7:0.09 Ce~(3+),0.12 Tb~(3+),0.30 Mn~(2+)can emit warm white light.The sample shows good thermal stability.At 150℃,the emission intensity for Ce~(3+)(360 nm),Tb~(3+)(545 nm) and Mn~(2+)(655 nm) decreases to 63%,69%,and 72% of its initial intensity,respectively.Moreover,the sample obtains good stability after 10 cycles between room temperature and150℃.     

Optical studies of Y_3(Al,Ga)_5O_(12):Ce~(3+),Cr~(3+),Nd~(3+) nano-phosphors obtained by the Pechini method

The Y3(AI,Ga)_5O_(12):Ce~(3+),Cr~(3+),Nd~(3+)(YAGG) nano-phosphors with homogeneous particle-size distribution,low aggregation and average crystalline size of about 65 nm were obtained using a modified Pechini method.Only slight aggregation of the crystallites occurs after post-annealing at 1100℃.The intense Ce~(3+)bands in the excitation spectra of the Ce~(3+),Cr~(3+),Nd~(3+)co-doped materials monitoring the Cr~(3+) emission at 690 nm indicate energy transfer from Ce~(3+) to Cr~(3+).Weak Nd~(3+) lines are observed,as well.In addition,the emission of Nd~(3+)at 1060 nm with excitation of Ce~(3+) and Cr~(3+) confirms the Ce~(3+)/Cr~(3+)to Nd~(3+)energy transfer.The short average luminescence decay times for the Ce~(3+) emission indicate the Ce~(3+)/Cr~(3+)to Nd~(3+)energy transfer.Eventually,the Y_3(AI,Ga)_5O_(12):Ce~(3+),Cr~(3+),Nd~(3+) nano-phosphors exhibit persistent luminescence originating from the 4f~3→4f~3 transitions of Nd~(3+) which matches well to the first biological window to be used in bioimaging applications.     

Humidity sensing properties of La~(3+)/Ce~(3+)-doped TiO_2-20 wt.% SnO_2 thin films derived from sol-gel method

The humidity sensing properties of La3+/Ce3+-doped TiO2-20 wt.%SnO2 thin films were studied.Sol-gel method was employed to prepare the films on alumina substrates.By constructing a humidity-impedance measuring system,the sensing behaviors were inspected for the films sintered at different temperatures.Experimental results showed that,0.5 wt.% of La2O3 or Ce2O3 doped films sintered at 500 °C for 2 h had the best humidity sensing properties,the impedance decreasing from 109 ? to below 104 ? in the humidity range of 15-95 RH%.Moreover,Ce3+-doping had better humidity sensing properties than La3+-doping.The doping mechanism was discussed in terms of phase composition,granularity of crystalline and segregation of rare earth ions at grain boundaries.     

Effect of grain size on thermal stability and oxygen storage capacity of Ce0.17Zr0.73La0.02Nd0.04Y0.04O2 solid solutions

Nanostructured CeO_2-ZrO_2 materials are an irreplaceable constituent in catalytic systems for automobile exhaust purification due to their unique oxygen storage capacity(OSC). However, traditional CeO_2-ZrO_2 materials are easy to sinter at high temperature, which causes a sharp decrease of OSC. In this paper,La~(3+) , Nd~(3+) and Y~(3+) are chosen as dopants for CeO_2-ZrO_2 to improve anti-sintering and OSC properties.The Ce_(0.17) Zr_(0.73) La_(0.02) Nd_(0.04) Y_(0.04) O_2 powders(CZLNY) were prepared by co-precipitation method. The effects of grain sizes with different mixed chlorinated solution concentrations on performances were investigated. X-ray diffraction(XRD) and transmission electron micrograph(TEM) were performed to calculate the grain sizes of CZLNY. The specific surfaces, OSC and redox properties were investigated by N_2 adsorption/desorption and temperature programmed reduction(H2-TPR). The results show that introducing La~(3+) , Nd~(3+) and Y~(3+) into CeO_2-ZrO_2 lattice can improve the stability of phase structure and anti-sintering ability. Moreover, low concentration of mixed chlorinated solution remarkably improves structural and textural properties of CZLNY. Relatively large fresh grain exhibits superior thermal stability and OSC under the condition of being calcined at 800℃ for 3 h. The specific surface and OSC are42.37 m~2/g and 333.13 mmol/g after calcining at 1000℃ for 10 h, respectively. This is owing to the low sintered driving force of large grain and long-range migration energy of large pores during the sintering process, which are beneficial to the stability of structure in CZLNY materials.     

Doping effect of rare-earth (lanthanum,neodymium and gadolinium) ions on structural,optical, dielectric and magnetic properties of copper nanoferrites

Copper and rare earth-doped (RE = La, Gd, Nd) CuFe_1.85RE_0.15O₄ nanoferrites were prepared using the sonochemical method. The effective doping of rare-earth (La³⁺, Nd³⁺, Gd³⁺) ions with copper nanoferrites was confirmed by X-ray diffraction. The tetrahedral and octahedral sites of the nanoferrites were identified through the Fourier transform infrared spectra. The doping of rare-earth elements enhances the optical bandgap energy of the nanoferrites that are observed through Ultraviolet–DRS spectra. The oxidation state of the elements Cu 2p, La 3d, Nd 3d, Gd 3d, Fe 2p and O 1s was analyzed. Scanning electron microscopy images indicate a spherical morphology with agglomeration to some elongate. The values of dielectric constant and conductivity decrease considerably due to doping rare-earth ions in copper nanoferrites. Low saturation magnetization and high coercivity values of rare earth-doped copper nanoferrites are observed from the typical hysteresis curves.     

Catalytic combustion of toluene over Pd-based monolithic catalysts with a novel washcoat Ce0.8Zr0.15La0.05Oδ

Two novel washcoats Ce_0.8Zr_0.15La_0.05O_δ and Ce_0.8Zr_0.2O₂ was prepared by an impregnation method, which acted as a host for the active Pd component to prepare Pd/Ce_0.8Zr_0.15La_0.05O_δ/substrate and Pd/Ce_0.8Zr_0.2O₂/substrate monolithic catalysts for toluene combustion. The washcoats was characterized by X-ray diffraction (XRD), Raman spectroscopy, Brunauner-Emmett-Teller (BET), and H₂-temperature-programmed reduction (H₂-TPR). The result indicated that both the washcoats had strong vibration-shock resistance according to ultrasonic test. Doping La³⁺ into CeO₂-ZrO₂ solid solution could generate more oxygen vacancies, and could inhibit the sinter of CeO₂-ZrO₂ solid solution when calcined at high temperatures (800, 900 and 1000 °C). The washcoat Ce_0.8Zr_0.15La_0.05O_δ had much better redox properties. The reductive temperature of Ce⁴⁺ species shifted to low temperature by 60 °C when the washcoats calcined at high temperatures (800, 900 and 1000 °C). The Pd/Ce_0.8Zr_0.15La_0.05O_δ/substrate monolithic catalyst calcination at 500 °C had the best catalytic activity and the 95% toluene conversion at a temperature as low as 190 °C. When calcined at low temperature (500 and 700 °C), the catalytic activity has little improvement, however, when calcined at high temperature, the catalytic activity of Pd/Ce_0.8Zr_0.15La_0.05O_δ/substrate monolithic catalysts had significant improvement. As catalyst washcoat, the Ce_0.8Zr_0.15La_0.05O_δ had better thermal stability than the washcoat Ce_0.8Zr_0.2O₂, the developed Pd/Ce_0.8Zr_0.15La_0.05O_δ/substrate monolithic catalyst in this work was promising for eliminating Volatile organic compounds.     

Luminescent properties of Ce3+, Er3+ co-doped La3Si6N11

In order to obtain near-infrared phosphor pumped by blue chip with high luminous efficiency, a novel near-infrared phosphor Ce³⁺/Er³⁺ doped La₃Si₆N₁₁ was designed and firstly prepared via conventional solid-state reactions. The structure and morphology of Ce³⁺/Er³⁺ doped La₃Si₆N₁₁ were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Compared with Er³⁺ doped La₃Si₆N₁₁, the emission intensity of the Ce³⁺, Er³⁺ co-doped phosphor can be increased more than 5 times. Meanwhile, the mechanism of energy transfer from Ce³⁺ to Er³⁺ is confirmed according to the excitation, emission spectra and decay lifetimes curve. Above results suggest that La₃Si₆N₁₁:Ce³⁺,Er³⁺ is a promising near-infrared phosphor for blue pumped LEDs (light-emitting diodes).     

A fluorescent probe based on a spiropyran for sensitive detection of Ce~(3+) ion

A spiropyran-based probe was developed.It serves as a fluorescence turn-on probe for selective detection of Ce~(3+) in both ethanol and aqueous(water/ethanol,1:9 or 9:1,v/v) media.Ce~(3+) can induce photochromism of the probe though the probe exhibits negligible photochromic property by itself.The probe is sensitive to Ce~(3+) and the detection limit reaches 1.7 μmol/L.It exhibits a high selectivity for Ce~(3+)ion over other common metal cations including Li~+,Na~+,Ag~+,Sr~(2+),Ni~(2+),Co~(2+),Hg~(2+),Zn~(2+),Cr~(3+),Al~(3+),Fe~(3+) and Bi~(3+) and lanthanide ions Nd~(3+),Yb~(3+) and La~(3+).The probe may be used for quantitative determination of the concentration of Ce~(3+) ion in a range of 1-10 μmol/L and for application to environmental water samples.Sensing mechanism of the probe towards Ce~(3+) ion is proposed.     

Color-tunable Ca10Na(PO4)7:Ce3+/Tb3+/Mn2+ phosphor via energy transfer

A series of Ca_(10)Na(PO_4)_7:Ce~(3+)/Tb~(3+)/Mn~(2+)(CNPO:Ce~(3+)/Tb~(3+)/Mn~(2+)) phosphors with high brightness were synthesized by high-temperature solid-state method. X-ray diffraction(XRD), scanning electron microscopy(SEM), diffuse reflectance spectra(DRS), photo luminescence(PL) spectra, luminescence decay curves and thermally stability were performed to characterize the as-prepared samples. For Ce~(3+)-doped samples, an intense and broad band emission is present under 265 nm excitation. When Ce~(3+) and Tb~(3+)are codoped, energy transfer(ET) process from Ce3+ to Tb3+ is demonstrated with electric dipole-dipole interaction. The internal and external quantum efficiencies(QEs) of CNPO:0.15 Ce~(3+), 0.04 Tb~(3+), 0.005 Mn~(2+)are measured to 76.79% and 54.11% under 265 nm excitation and temperature-dependent PL intensity can remain 51.78% at 150 ℃ of its initial intensity at 25 ℃. It is indicated that single-phased white lightemitting CNPO:Ce~(3+)/Tb~(3+)/Mn~(2+) phosphor can serve as a promising phosphor for illumination devices.     

Tunable emission,energy transfer and thermal stability of Ce3+, Tb3+ co-doped Na2BaCa(PO4)2 phosphors

A series of single Ce³⁺ doped and Ce³⁺ and Tb³⁺ co-doped Na₂BaCa(PO₄)₂ (NBCP) phosphors was synthesized by conventional solid-stated reaction method. The crystal structure, luminescence properties, thermal stability and energy transfer were carefully investigated. Ce³⁺ is inferred to substitute the Ba²⁺ site in NBCP lattice. The color-tunable emission from blue to green is observed by adjusting Tb³⁺ concentration among NBCP:0.03Ce³⁺,yTb³⁺ phosphors. The energy transfer behavior from Ce³⁺ to Tb³⁺ ions is both illustrated by co-doped PL spectra and decay curves. The energy transfer efficiency is as high as 91.5%. The mechanism of energy transfer is resonance type of dipole-dipole transition. In this work, the optimal phosphor exhibits the excellent thermal stability which keeps at 94.9% of that initial value at room temperature when temperature reaches to 150 °C. The Ce³⁺ and Tb³⁺ co-doped NBCP phosphor is a promising candidate for the application in the general lighting and display fields.     

Preparation and characterization of Er3＋-Yb3＋-Ce3＋ co-doped transparent glass ceramic containing nano Cas（PO4）3F crystals

A transparent glass ceramic tri-doped with Ce3+/Er3+/Yb3+ was fabricated by the high-temperature melting technique and following heat-treatment.X-ray diffraction and transmission electron microscope results demonstrated that Ca5(PO4)3F(FAP) nanocrystals,possessed with preferable emission performances for the 1.54 m transition for doping Er3+,were homogeneously precipitated among the glass matrix with a mean size of 30 nm.Addition of Ce3+ greatly enhanced 1.54 m fluorescence of Er3+ by the cross relaxation energy transfer between Er3+ and Ce3+.Meanwhile,incorporation of Ce3+ dramatically decreased the visible upconversion emission intensity of glass ceramic than that of glass,suggesting that Ce3+ might incorporate into the FAP nanocrystals.The properties of this transparent glass ceramic showed the potential application as an efficient 980 nm pumped infrared laser medium.     

Enhanced afterglow performance of CaAl_2O_4:Eu~(2+),Nd~(3+) phosphors by co-doping Gd~(3+)

In order to effectively improve the afterglow properties of CaAl_2 O_4:Eu~(2+),Nd~(3+) phosphors,a series of Ca_(0.982-x)Al_2 O_4:0.012 Eu~(2+),0.006 Nd~(3+),xGd~(3+)(x=0,0.012,0.024,0.036,0.048,0.060 mol) phosphors were prepared by a high-temperature solid-phase approach.Crystalline composition and microstructure were characterized by XRD,TEM,HRTEM,and XPS,luminescence properties were systematically analyzed by fluorescence spectra,afterglow decay curves and TL glow curve.Results show that all of Ca_(0.982-x)Al_2 O_4:0.012 Eu~(2+),0.006 Nd~(3+),xGd~(3+)phosphors belong to monoclinic CaAl_2 O_4,without other cystalline phase.The blue emission at 442 nm is observed,which is assigned to the 4 f~65 d→4 f~7 transition of Eu~(2+) ions.Doping with appropriate amount of Gd~(3+) ions(x=0.036 mol) significantly improves the afterglow properties of phosphors,but the excessive doping of Gd~(3+) induces the fluorescent quenching.The doping of moderate Gd3+changes the traps states,the trap depth varies from 0.598 to 0.644 eV and the trap concentration is also greatly improved,thus significantly improving afterglow performance.     

Synthesis and optical properties of LiNd(PO_3)_4 nanocrystals dispersion in DMSO/TBE

Lanthanide doped nanocrystals with strong fluorescence, long lifetime at high doping concentrations have great potential application in bio-imaging and liquid gain medium. LiNd(PO_3)_4(LNP) crystal was reported to be one of the most excellent laser crystals with high Nd3+ concentration, and their nanocrystals synthesized via improved combustion method for the first time had strong emission intensity and long fluorescence lifetime of 122 μs. Besides,LiNd(PO_3)_4 nanocrystals can be dispersed in mixed solvents of DMSO/TBE(CHBr2 CHBr2) to form a transparent colloidal dispersion, and Judd-Ofelt theory was used to evaluate their optical parameters. In summary, LiNd(PO_3)_4 nanocrystals possess long lifetime(116 μs), low solvents quenching rate(4.9%), large emission cross section(7.63 × 10~(-20) cm~2) and high quantum yield(35.2%) under high Nd3+ ions concentration(1×10~(20) cm~(-3)), which would be the most competitive colloidal gain medium of optical amplification and laser with LD pump and potential biomaterial with low particles concentration.     

Optical and electrical conductivity properties of rare earth elements (Sm,Y, La,Er) co-doped CeO2

In this research, un-doped CeO₂ and Ce_0.85La_0.10M_0.05O₂ (M: Sm, Er, Y) compounds were synthesized by hydrothermal method and the multi-functional properties are reported. Oxygen defects were created with the additives of rare earth ions. The electrical and luminescence behaviors of the synthesized compounds were investigated in accord with the types of additives. The synthesized products were characterized by X-ray diffraction (XRD) analysis, Brunauer–Emmett–Teller (BET) measurement, UV–vis diffuse reflectance spectroscopy (DRS), scanning electron microscopy (SEM), photoluminescence (PL) spectroscopy and electrochemical impedance spectroscopic (EIS). All synthesized compounds are found to be nano-structured and have cubic phase. The total conductivity of all samples was calculated. Hence, the total conductivity of un-doped CeO₂, Ce_0.85La_0.10Y_0.05O₂, Ce_0.85La_0.10Er_0.05O₂ and Ce_0.85La_0.10Sm_0.05O₂ is found to be 2.07 × 10^?10, 5.70 × 10^?4, 1.0 × 10^?3 and 0.0747 S/cm, respectively. Also, bandgap energy (E_g) of these samples calculated from UV visible absorption spectra is discussed, and the optical results show variation between 3.2 and 2.15 eV. Additionally, the luminescence properties of the compounds were investigated and different emissions occur depending on the additive type. Accordingly, photoluminescent emission spectra of Ce_0.85La_0.10Y_0.05O₂, Ce_0.85La_0.10Er_0.05O₂ and Ce_0.85La_0.10Sm_0.05O₂ phosphors indicate that these phosphors have red, green and orange-red colors, respectively.     

Luminescence properties of a single-host phosphor Bal.8-wSrwLi0.4SiO4： cea＋,Eu2＋,Mn2＋ for WLED

In order to obtain a single-host-white-light phosphor,a series of Ba1.8-w-x-y-zSrwLi0.4-xCexEuyMnzSiO4(BSLS:Ce3+,Eu2+,Mn2+)powder samples were synthesized via high temperature solid-state reaction.The structure and photoluminescence properties were investigated.Under ultraviolet excitation,the emission spectra contained three bands:the 370-470 nm blue band,the 470-570 nm green band and the 570-700 nm red band,which arose from the 5d→4f transitions of Ce3+ and Eu2+,and the 4T1→6A1 transition of Mn2+,respectively.The excitation spectra of the emissions of Ce3+ and Mn2+ ions showed the energy transfer from Ce3+ to Mn2+.White light emission was obtained from the tri-doped samples of appropriate doping concentration under 310-360 nm excitation.     

LSM particle size effect on the overall performance of IT-SOFC

In this paper, we reported the fuel cell performance with La0.8Sr0.2MnO3 (LSM)/Ce0.8Sm0.2O1.9 (SDC) composite cathode prepared from LSM powders of different particle sizes via the silk-printing technique. It was found that the change in particle size of LSM nanoparticle from 40 to 90 nm resulted in an increase in the maximum power density from 132 to 228 mW/cm2 at 650 ℃ with H2 as fuel and O2 as oxidant. And the polarization resistance of the electrode decreased from 2.547 to 1.034 Ω·cm2. Concerning the particle size of electrode materials, a higher activity was anticipated with smaller particles because a large number of TPB or electrode surface sites along with a higher porosity could be developed. However, this study showed that the electrode prepared with particles of larger diameter had fine and uniform micro-structure resulting in higher power density and lower overpotential, where homogeneous distribution of particles and pores was beneficial for increasing the electrochemical active area and the electronic conductivity of the electrodes as well as the gas diffusion for the reactants.     

Samarium doped apatite-type orange-red emitting phosphor Ca_5(PO_4)_2SiO_4 with satisfactory thermal properties for n-UV w-LEDs

A novel single-phase Sm~(3+) activated Ca_5(PO_4)_2SiO_4 phosphor was successfully fabricated via a conventional solid-state method, which can be e fficie ntly excited by near ultraviolet(n-UV) light-emitting chips.The crystal structure and luminescence properties were characterized and analyzed systematically by using relevant instruments. The Ca_5(PO_4)_2SiO_4:Sm~(3+) phosphor shows an orange-red emission peaking at600 nm under the excitation of 403 nm and the optimal doping concentration of Sm~(3+) is determined to be 0.08, The critical distance of Ca_5(PO_4)_2SiO_4:0.08 Sm~(3+) is calculated to be 1.849 nm and concentration quenching mechanism of the Sm~(3+) in Ca_5(PO_4)_2SiO_4 host is ascribed to energy transfer between nearestneighbor activators. The decay time of Ca_5(PO_4)_2 SiO_4: 0,08 Sm~(3+) is determined to be 1.1957 ms. In addition, the effect of temperature on the emission intensity was also studied, 72.4% of the initial intensity is still preserved at 250 ℃, better thermal stability compared to commercial phosphor YAG:Ce~(3+) indicates that Ca_5(PO_4)_2SiO_4:0.08 Sm3+ has excellent thermal stability and active energy is deduced to be 0.130 eV.All the results demonstrate that orange-red emitting Ca_5(PO_4)_2SiO_4:0.08 Sm~(3+) phosphor exhibits good luminescent properties. Owing to the excellent thermal quenching luminescence property,Ca_5(PO4)_2SiO_4:0.08 Sm~(3+) phosphor can be applied in n-UV white light emitting diodes and serve as the warm part of white light.     

A novel blue-purple Ce~(3+) doped whitlockite phosphor:Synthesis,crystal structure,and photoluminescence properties

At present,the rare earth(RE) ions doped phosphors have attracted more and more attention because of their excellent properties.In this paper,a series of novel blue-purple β-Ca_3(PO_4)_2:Ce~(3+) phosphors were synthesized by a high temperature solid phase method.The X-ray diffraction(XRD),infrared spectrum,energy dispersive spectroscopy(EDS),scanning electron microscopy(SEM),X-ray photoelectron spectroscopy(XPS),photoluminescence excitation and emission spectra were used to investigate the crystal structure,composition and the luminescent properties of the resulting samples.The phosphor shows a strong absorption in the ultraviolet band.Under the excitation of 269 nm,the phosphor emits a strong purple fluorescence ranging from 360 to 520 nm.When Ce~(3+) doping content is 0.07 mol,the strongest luminescence intensity is reached,and the concentration quenching mechanism is dipole-dipole(d-d)interaction for Ce~(3+) based on Dexter theory.     

Magnetoelectric,Raman, and XPS Properties of Pb0.7Sr0.3[(Fe2/3Ce1/3)0.012Ti0.988]O3 and Pb0.7Sr0.3[(Fe2/3La1/3)0.012Ti0.988]O3 Nanoparticles

The Pb_0.7Sr_0.3[(Fe_2/3Ce_1/3)_0.012Ti_0.988]O₃ (PSFCT) and Pb_0.7Sr_0.3[(Fe_2/3La_1/3)_0.012Ti_0.988]O₃ nanoparticles were prepared by chemical synthesis route using polyvinyl alcohol as surfactant. X-ray diffraction pattern has been used to analyze the phase structure and average particles size. The phase structure is also confirmed by Raman spectra. The chemical states of Pb²⁺, Sr²⁺, Fe³⁺; Ti⁴⁺, Ce³⁺, La³⁺, and oxygen ions have been analyzed by X-ray photoelectron spectroscopy. The magnetoelectric coupling effect is confirmed by magnetic phase transition near ferroelectric phase-transition temperature. The magnetoelectric effect is also confirmed by measuring the value of magnetoelectric coefficient (α _E) as the function of applied dc magnetizing field under the influence of ac magnetic field of 10 Oe and frequencies of 847 and 997 Hz. The higher value of α _E is observed in PSFCT sample.     

Synthesis and characterization of YAG: Ce3+ fluorescence powders by co-precipitation method

YAG:Ce³⁺(Yttrium aluminum garnet) fluorescence powders were successfully prepared by co-precipitation method using aluminum nitrate, yttrium nitrate, cerous nitrate as the starting materials and ammonium carbonate as precipitant. The products were characterized by X-ray powder diffraction, luminescence spectrometer, transmission electron microscope (TEM). The XRD results showed that the obtained YAG:Ce³⁺ fluorescence powders had the crystalline structures of YAG at calcinations temperature of 900 °C and the TEM results showed that the grain diameters were about 100 nm. The YAG:Ce³⁺ fluorescence powders, synthesized by co-precipitation method, had the best luminescence property when the Ce doping amount was x=0.06 in the molecular formula of Y_3-xCe_xAl₅O₁₂, the calcinations time was 2 h and the calcinations temperature was 1000 °C.