Effect of B2O3 or SiO2 Fluxes on Morphology and Size of Pr-Doped CaTiO3 Phosphor Particles and on their Photoluminescence Properties

2011 ◽  
Vol 497 ◽  
pp. 31-37 ◽  
Author(s):  
Toru Kyomen ◽  
Ryuta Motani ◽  
Minoru Hanaya

Powder of Pr-doped CaTiO3 red phosphor was prepared at 1473 K by a conventional solid-state reaction method with addition of B2O3 or SiO2 as a flux. Primary particle sizes of the prepared samples were increased by using B2O3 flux but decreased by using SiO2 flux. Clear planes, edges, or steps were observed on surfaces of the primary particles. The intensity of photoluminescence induced by irradiation of light with a wavelength longer than ∼350 nm was enhanced about three times by using B2O3 flux. The intensity of photoluminescence induced by irradiation of light with a wavelength shorter than ∼350 nm was enhanced about twice by using either B2O3 or SiO2 fluxes. The origin for the flux effects is discussed.

2021 ◽  
pp. 21410001
Author(s):  
Yu Fan ◽  
Chin-Ta Chen ◽  
Yen-Tsu Wang ◽  
Cheng-Fu Yang

Phosphors with the compositions of [Formula: see text] ([Formula: see text], 0.015, 0.025, 0.035, and 0.045) are synthesized in a reduction atmosphere (5% H2 + 95% N2) using a solid-state reaction method. At first, the [Formula: see text] powder is synthesized at 1350[Formula: see text]C with a duration of [Formula: see text] h to find the optimum synthesizing time. SEM images show that the particle sizes increase with synthesizing time and as the synthesizing time is more than 4 h, the abnormal particles appear and the intensities at the emission peaks of photoluminescence excitation (PLE) and photoluminescence emission (PL) spectra decrease. Next, 1350[Formula: see text]C and 4 h are used as synthesized parameters, which are used to find the concentration quench effect of [Formula: see text] phosphors. As the concentration of [Formula: see text] ions of [Formula: see text] phosphors increases, the intensities at the emission peaks of PLE and PL spectra first increase and reach the maximum values at [Formula: see text], and then they decrease as the concentration of [Formula: see text] ions further increases. These results prove that the synthesizing time and concentration of [Formula: see text] ions are two important factors to affect the photoluminescence properties of [Formula: see text] phosphors.


2020 ◽  
Vol 8 (12) ◽  
pp. 762-769
Author(s):  
Ch. Atchyutha Rao ◽  
◽  
K.V.R. Murthy ◽  

Calcium Silicate phosphor acquires a higher luminous efficiency when it is doped with rare earth activated ions. Silicate phosphors are used for a fluorescent, a cathode-ray tube, a luminous body, a vacuum ultraviolet excitation light emitting element etc. The silicates of calcium are known for their thermal stability, high temperature strength, low thermal expansion, cheep residence and chemical inertness. The present paper reports on the synthesis, characterization and photoluminescence properties of Eu3+ doped calcium silicate phosphor prepared by conventional solid state reaction method heating at 12000C for 3 hrs. The received cakes are grounded for 30 minutes each. The phosphors are prepared and the received powder is subjected to PL, XRD, SEM, EDAX and CIE analysis. The following section discusses and the experimental results are mentioned in these phosphors. The present Phosphor can act as a host for red light emission in many display devices and technological applications.


2010 ◽  
Vol 160-162 ◽  
pp. 594-598
Author(s):  
Guo Jian Jiang ◽  
Jia Yue Xu ◽  
Hui Shen ◽  
Yan Zhang ◽  
Lin He Xu ◽  
...  

Zinc silicate-based (Zn2SiO4:Eu3+) long afterglow phosphors were produced by solid state reaction method. The effects of borax and Eu2O3 additive on the properties of fabricated products have been studied. The results show that, there is not much difference in phase compositions within the borax additive amount; however, their SEM morphologies are different. Borax additive can increase the grain size of the product. Some sintering phenomena could be observed in the sample with Eu2O3 addition. The fluorescence spectroscopy results indicate that, the emission peak of the sample with Eu3+ additive located at 612nm, which may be a good candidate for red phosphor applications. The luminescent mechanism of Zn2SiO4:Eu3+ is also discussed.


2016 ◽  
Vol 680 ◽  
pp. 228-232
Author(s):  
Xi Guang Gu ◽  
Ren Li Fu ◽  
Ye Tang ◽  
Fang Yang

Ce3+-doped 0.5La2O3-2SrO-0.5Al2O3 (LSA:Ce) phosphors had been successfully synthesized using a conventional solid-state reaction method under reducing atmosphere (H2/N2 =1/5). The phase, morphologies and luminescence properties of the LSA:Ce phosphors were investigated. The emission intensity of LSA:Ce phosphors was improved by the addition of SrF2 as flux, and red shift of PL spectra peak was observed in this phosphors. Research results shown that the LSA:Ce phosphors have the potential to meet the development of white light-emitting diodes.


2018 ◽  
Vol 6 (41) ◽  
pp. 19967-19973 ◽  
Author(s):  
Zhenyong Cen ◽  
Yu Huan ◽  
Wei Feng ◽  
Yan Yu ◽  
Peiyao Zhao ◽  
...  

Lead-free (1 − x)(0.96K0.46Na0.54Nb0.98Ta0.02O3–0.04Bi0.5(Na0.82K0.18)0.5ZrO3)–xCaZrO3 ((1 − x)(0.96KNNT–0.04BNKZ)–xCZ) piezoelectric ceramics were prepared by the conventional solid-state reaction method.


RSC Advances ◽  
2018 ◽  
Vol 8 (28) ◽  
pp. 15613-15620 ◽  
Author(s):  
Xiaochun He ◽  
Ruiqing Chu ◽  
Zhijun Xu ◽  
Zhongran Yao ◽  
Jigong Hao

Lead-free ceramics, SrBi2Nb2O9–xBi2O3 (SBN–xBi), with different Bi contents of which the molar ratio, n(Sr) : n(Bi) : n(Nb), is 1 : 2(1 + x/2) : 2 (x = −0.05, 0.0, 0.05, 0.10), were prepared by conventional solid-state reaction method.


2007 ◽  
Vol 22 (4) ◽  
pp. 958-964 ◽  
Author(s):  
Zhaosheng Li ◽  
Jinhua Ye ◽  
Zhigang Zou

MIn(WO4)2 (M = Li, Na, and K) with InO6 and WO6 octahedra were synthesized via a conventional solid-state reaction method. The photophysical and photocatalytic properties were studied. Compared with WO3, which is unable to evolve H2 from an aqueous CH3OH solution under illumination, the three materials can evolve H2 and O2 from aqueous solutions with CH3OH and AgNO3 sacrificial reagents, respectively. The activity order of photocatalytic H2 evolution is NaIn(WO4)2 > LiIn(WO4)2 > KIn(WO4)2 under irradiation (λ > 200 nm). Under irradiation (λ > 300 nm), however, LiIn(WO4)2 has a high activity for photocatalytic H2 evolution over NaIn(WO4)2. It is also noteworthy that LiIn(WO4)2 and NaIn(WO4)2 exhibit the ability to split pure water. The results suggest that the bottoms of the conduction bands in these photocatalysts are raised to meet the potential requirements of photocatalytic H2 evolution.


2007 ◽  
Vol 336-338 ◽  
pp. 272-274
Author(s):  
S.S. Cheng ◽  
J. Luo ◽  
Zhao Xian Xiong

Microwave ceramics of Ba(Mg0.2/3Zn0.8/3Nb2/3)O3 and Ba1-xSrx(Mg0.2/3Zn0.8/3Nb2/3)O3 were synthesized with conventional solid-state reaction method. Dielectric properties of the samples were studied as functions of compositions and sintering temperatures. Experimental results show that a higher Q×f value is reached by substituting Zn ions with Mg ions and a near-zero temperature coefficient of resonant frequency is obtained by replacing Ba ions with Sr ions.


2009 ◽  
Vol 23 (01) ◽  
pp. 87-95 ◽  
Author(s):  
HAOSHAN HAO ◽  
QINGLIN HE ◽  
CHANGQING CHEN ◽  
HONGWEI SUN ◽  
XING HU

Ca 3-x Bi x Co 4 O 9(x = 0.0, 0.3) samples have been prepared at 1223 K by conventional solid-state reaction method. XRD and SEM investigations reveal that c-axis-oriented structure could be formed in Ca 2.7 Bi 0.3 Co 4 O 9 samples, whereas grains in Ca 3 Co 4 O 9 samples distribute randomly. Moreover, Bi doping increases the grain size and relative density of Ca 2.7 Bi 0.3 Co 4 O 9. The electrical conductivity along the ab plane for Ca 2.7 Bi 0.3 Co 4 O 9 is about four times as large as that along the c-axis, but the Seebeck coefficient is almost isotropic, which leads to a remarkable rise of the power factor in ab plane for Ca 2.7 Bi 0.3 Co 4 O 9 compared with untextured Ca 3 Co 4 O 9. The textured structure in Ca 2.7 Bi 0.3 Co 4 O 9 sample should be attributed to the effect of Bi doping.


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