Synthesis and Luminescent Properties of Pr3+ Activated KNbO3 Phosphors by Sol-Gel Combustion Process

2013 ◽  
Vol 873 ◽  
pp. 783-786 ◽  
Author(s):  
Jun Ji Zhang ◽  
Hui Zhou ◽  
Ji Shi Chen ◽  
Ting Tang ◽  
Yuan Zheng Hao
Keyword(s):  
Particle Size ◽  
Single Phase ◽  
Sol Gel ◽  
Combustion Process ◽  
Luminescent Properties ◽  
Phase Evolution ◽  
Combustion Method ◽  
Treatment Temperature ◽  
Nanoscale Particles ◽  
Gel Combustion

Praseodymium doped KNbO3 (KNbO3:Pr) phosphors were synthesized by a facile solgel combustion method. Phase evolution, particle size and luminescent properties of the powders synthesized at various temperatures were investigated. Single-phase KNbO3:Pr nanoscale particles were obtained at 600°C by directly crystallizing from amorphous precursors. The particle size of KNbO3:Pr powders can be well controlled by varying the heat treatment temperature. Under the excitation of 450 nm, KNbO3:Pr phosphors showed the well-known Pr3+ emissions associated with the 4f inter-level electronic transitions in Pr3+ ions.

Perovskite gels combustion synthesis from rare earth aluminates. Development of multifuncional properties.

MRS Advances ◽  
2020 ◽  
Vol 5 (62) ◽  
pp. 3301-3313
Author(s):  
A. Barrera ◽  
M.L. Chávez ◽  
E. Chavira ◽  
T.A. García ◽  
J.M.E. Carreto
Keyword(s):  
Particle Size ◽  
Rare Earth ◽  
Sol Gel ◽  
Luminescent Properties ◽  
Combustion Method ◽  
Ceramic Pigments ◽  
Material Development ◽  
Gel Combustion ◽  
Gel Combustion Method ◽  
Paramagnetic Properties

AbstractThe purpose of this work was the synthesis of the perovskites with rare earth, by gel combustion method with pigmenting, magnetic and luminescent properties. The synthesis of perovskite structure is important for material development, with multi features. In this work, the synthesis was from metal oxides by the method of combustion of gels at 500 °C, for 10 s. Color of perovskites obtained, with nanometric particle size (31-44 nm) was analysed by CIEL*a*b* with tonalities ranged from white to pink except for Pr-perovskites with yellow and brown. Its paramagnetic properties were verified by magnetic susceptibility. Its luminescence was at 260 nm, except for Pr-perovskites. This work opens an important opportunity to develop ceramic pigments with perovskites structures integrating other properties as luminescence and paramagnetism by combustion sol-gel method.

Low temperature synthesis of ultrafine Pb(Zr, Ti)O3 powder by sol-gel combustion

1997 ◽  
Vol 12 (10) ◽  
pp. 2518-2521 ◽  
Author(s):  
J. Schäfer ◽  
W. Sigmund ◽  
S. Roy ◽  
F. Aldinger
Keyword(s):  
Lead Zirconate Titanate ◽  
Single Phase ◽  
Sol Gel ◽  
Combustion Process ◽  
Lead Zirconate ◽  
Homogeneous Distribution ◽  
Low Temperature Synthesis ◽  
Metal Nitrates ◽  
Gel Combustion ◽  
Diffusion Paths

Lead zirconate titanate powders are derived from a novel aqueous-based citrate-nitrate/oxynitrate sol-gel combustion process. Aqueous solutions of metal nitrates or oxynitrates are transformed into gels with citric acid under heating. The received gels undergo a self-propagating combustion reaction on heating to 180 °C and subsequently yield voluminous ashes. These ashes form single phase perovskite Pb(Zr0.53Ti0.47)O3 powder with a specific surface area of 8 m2/g upon calcination at 550 °C. The ashes show a homogeneous distribution of lead, zirconium, and titanium ions which guarantees short diffusion paths in solid state formation of PZT perovskite. The redox behavior of the gels was studied with the help of DTA experiments. Powders are characterized in terms of XRD, SEM, and EDX analysis.

Synthesis of BiFeO3-PbTiO3 Powders by Sol-Gel Auto-Combustion Process

2007 ◽  
Vol 280-283 ◽  
pp. 609-612 ◽  
Author(s):  
Hao Sheng ◽  
Zhen Xing Yue ◽  
Zhi Lun Gui ◽  
Long Tu Li
Keyword(s):  
Citric Acid ◽  
Aqueous Solutions ◽  
Ir Spectra ◽  
Single Phase ◽  
Sol Gel ◽  
Combustion Process ◽  
Combustion Method ◽  
Metal Nitrate ◽  
Auto Combustion

BiFeO3-PbTiO3 powders were synthesized by a novel sol-gel auto-combustion method. The gels, transformed from the aqueous solutions of metal nitrate and citric acid, undergo a selfpropagatingcombustion process when being ignited and yield voluminous ashes. These ashes are single phase perovskite BiFeO3-PbTiO3 powders. The redox behaviors of the dried gels were studied by DTA-TG technique and IR spectra. The synthesized powders were characterized in terms of XRD, SEM and BET techniques.

Synthesis of LaFeO3 Nano-Powders by Self-Propagating Combustion Method of Sol-Gel

2013 ◽  
Vol 544 ◽  
pp. 17-20
Author(s):  
Yan Feng Zhu ◽  
Wei Liang Liu ◽  
An Hua Wu ◽  
Zhen Qian Feng ◽  
Chuan Yong Wang ◽  
...  
Keyword(s):  
Particle Size ◽  
Ignition Temperature ◽  
Room Temperature ◽  
Single Phase ◽  
Sol Gel ◽  
Chelating Agent ◽  
Combustion Method ◽  
Hysteretic Loop ◽  
Nano Powder ◽  
Auto Combustion

Nanocrystalline LaFeO3 with particle size of about 50 nm was directly synthesized by sol–gel auto-combustion method at room temperature. The overall process involves three steps: formation of homogeneous sol; formation of dried gel; and combustion of the dried gel. Single phase nanocrystalline LaFeO3 powders were successfully synthesized by the sol–gel self-propagation combustion method using glycin (C2H5NO2) as the chelating agent. Discuss the synthesis products by DTA/TG, XRD and SEM. The experiment results show that the LaFeO3 nano-powder was got from dried gel of G/M=1:1 at 300°C ignition temperature and then holding 2h at 800°C.The LaFeO3 nano-powder is about 50nm with excellent dispersibility. The hysteretic loop show LaFeO3 nanopowders have the character of ferromagnetism, the coercivity of the nanocrystalline LaFeO3 is 99G, while the saturation is only 2.8 emug-1.

The Phase Composition of Re3+ (Re=Lu, Gd, La) Co-Doped YAG:Ce and its Luminescent Properties

2010 ◽  
Vol 663-665 ◽  
pp. 129-132 ◽  
Author(s):  
Le Zhang ◽  
Hao Yang ◽  
Peng De Han ◽  
Li Xi Wang ◽  
Qi Tu Zhang
Keyword(s):  
Phase Composition ◽  
Sol Gel ◽  
Luminescent Properties ◽  
Blue Shift ◽  
Combustion Method ◽  
Emission Peak ◽  
Garnet Structure ◽  
Gel Combustion ◽  
Gel Combustion Method ◽  
Co Doped

A series of Re3+ (Re=Lu, Gd, La) co-doped YAG phosphors were successfully synthesized by a sol-gel combustion method and characterized with XRD and photoluminescent spectrum. The phase composition and luminescent properties of YAG:Ce under different Re co-doped concentrations were investigated. Doping only 50 mol% of La3+ to replace Y3+ sites, the main phase of sample has transformed into LaAlO3. While the concentration of Gd3+ reached 90~99 mol%, it was still cubic YAG. Lu3+ could replace Y3+ ions completely with the garnet structure. The location of the emission peak of Gd-codoped YAG:Ce3+ shifted to red region 21 nm corresponding to the maximum emission intensity before the appearance of GdAlO3. In addition, it had a 24 nm blue shift when Y3+ replaced by Lu3+ completely.

scholarly journals THERMOCHEMICAL SYNTHESIS OF NANOSTRUCTURED Y2O3: Eu3+ AND Y2O3:Bi3+,Eu3+ POWDERS AND THEIR LUMINESCENT PROPERTIES

2017 ◽  
Vol 12 (1) ◽  
pp. 31-38 ◽  
Author(s):  
O. V. Davydova ◽  
N. E. Drobyshevskaya ◽  
E. N. Poddenezhny ◽  
A. A. Boiko
Keyword(s):  
Particle Size ◽  
Average Particle Size ◽  
Combustion Process ◽  
Luminescent Properties ◽  
Visual Observation ◽  
Treatment Temperature ◽  
Average Particle ◽  
X Ray Diffraction ◽  
X Ray ◽  
Thermochemical Synthesis

This article describes a new method of thermochemical synthesis of luminescent nanostructured powders of Y2O3:Eu3+ and Y2O3:Bi3+, Eu3+ based on the burning of nitrate salts in the presence of a complex organic fuel consisting of a mixture of carbamide and hexamethylenetetramine (HMTA). It is established that using a combined fuel - a mixture of carbamide and HMTA - in a thermochemical reaction followed by calcination of the precursor at 650ºC gives more friable powders than the reaction with pure carbamide as a fuel, with a large amount of cavities. It is shown that when preparing Y2O3:Eu3+powders, complex compounds of anhydrous nitrates Y(NО3)3∙3СO(NH2)2 and Eu(NO3)3∙6CO(NH2)2 with urea are formed at the gel stage. They are decomposed at a higher temperature (about 1200ºС) resulting from the combustion process. As a result, corresponding crystalline oxides are formed. The europium ions replace a part of the yttrium ions in the structure of Y2O3 favouring the formation of a luminescent powder. X-ray diffraction, scanning electron microscopy, and photoluminescence spectroscopy have been used to characterize these powders. The powders synthesized in this manner (calcination at 650ºC) show a sharp peak in the X-ray diffraction picture at 2θ = 28.94° corresponding to crystalline Y2O3 particles with average particle size 62.3 nm. However, when treatment temperature is increased to 1200ºC, and the process duration is 1 h, the average particle size increases to 0.25 microns. Measurement of photoluminescence spectra of the samples revealed a maximum in the red region (λ=612 nm) when exciting at a wavelength of 395 nm (violet radiation). Luminescence intensity increases by 15% when introducing bismuth ions into the Y2O3 matrix and decreases by 30% when calcinating the Y2O3:Eu3+ powders at 1100ºС. The nanostructured Y2O3:Bi3+, Eu3+ powders obtained by the burning method can be applied in systems for protecting valuable security and industrial products, because these powders have special luminescent characteristics allowing to make visual observation of texts and tags under the radiation of LED sources without application of UV-lamps.

Sign in / Sign up

Export Citation Format

Share Document