Preparation and Research on Luminescent Properties of Eu-Doped TiO2-ZnO Composite Powders

2013 ◽  
Vol 652-654 ◽  
pp. 622-627 ◽  
Author(s):  
Bao Xiang Jiao ◽  
Meng Ting Li ◽  
Xia Zhang ◽  
Xu Wang

The Eu-doped TiO2nanocrystals with different content of Eu3+and the Eu-doped TiO2-ZnO composite powders with different content of ZnO were prepared by sol-gel method. The X-ray diffraction (XRD) spectra and photoluminescence(PL) spectra indicated that all of the Eu-doped TiO2have anatase structure. It indicated that the incorporation of Eu3+can inhibit the transformation of TiO2from anatase to rutile phase. With the increase of the content of Eu3+, the luminous intensity first increased and then decreased, and luminescent properties were best when the content of Eu3+is 1.1%. Considering the Eu-doped TiO2-ZnO composite powders, with the increasing of the proportion of ZnO, a Zn2TiO4phase has been gradually generated. When the content of ZnO up to 40%, the luminescent properties are the best.

2016 ◽  
Vol 35 (9) ◽  
pp. 963-966
Author(s):  
Yanzhi Meng ◽  
Xiaomin Wang ◽  
Yi Shen ◽  
Xiaoli Wei ◽  
Liying Han ◽  
...  

AbstractThe red long-lasting phosphors (LLPs) ZnxCa1–xTiO3:yPr3+ (ZCTP) were successfully prepared via the sol–gel method. The effects of Zn2+ content and Pr3+ molar concentration on the luminescent properties of ZCTP LLPs were characterized by X-ray diffraction, excitation and emission spectra, long-lasting decay curves and thermoluminescence (TL) curves. In this study, the results indicated that luminescent properties of Zn0.2Ca0.8TiO3:0.2 %Pr3+ phosphor was the best. In addition, when Pr3+ molar concentration reached 0.8 mol %, concentration quenching effect was obvious.


2001 ◽  
Vol 676 ◽  
Author(s):  
Carla Cannas ◽  
Mariano Casu ◽  
Roberta Licheri ◽  
Anna Musinu ◽  
Giorgio Piccaluga ◽  
...  

ABSTRACTA Y2O3-SiO2 nanocomposite doped with Eu3+ was obtained by a sol-gel method and characterized by X-ray diffraction, IR, 29Si NMR and laser-excited luminescence spectroscopy. It was found that small (2-3 nm) yttria nanoparticles are homogeneously dispersed in, and interacting with, the amorphous silica matrix. Luminescence spectroscopy indicates that the Eu3+ ion is preferentially located inside or at the surface of highly disordered Y2O3 nanoparticles. These luminescent nanocomposites form a class of materials which could find applications in the field of phosphors.


2013 ◽  
Vol 200 ◽  
pp. 22-26 ◽  
Author(s):  
Pawel Popielarski ◽  
Kazimierz Paprocki ◽  
Waclaw Bala ◽  
Agnieszka Banaszak-Piechowska ◽  
Karolina Walczyk ◽  
...  

Confocal Raman spectroscopy has been applied to investigate blend polycarbonate and ZnO thin layers with different thicknesses and different content of ZnO. The admittance spectroscopy have been applied to correlation of optical and electrical properties of these layers used in electroluminescence diodes and photovoltaic cells. The I-V (DC and AC) characteristics and thermally stimulated current (TSC) have been applied to the study of the deep levels in ZnO thin films grown by sol-gel method onto Si substrates. The surface spectroscopy morphology of the samples were investigated by scanning microscopy and X ray diffraction.


2018 ◽  
Vol 8 ◽  
pp. 184798041880064 ◽  
Author(s):  
VM Maphiri ◽  
BF Dejene ◽  
TE Motaung ◽  
TT Hlatshwayo ◽  
OM Ndwandwe ◽  
...  

Mg1.5Al2O4.5: x% Eu3+ (0 ≤ x ≤ 2) nanopowders were successfully synthesized via sol–gel method. The X-ray diffraction (XRD) spectrum revealed that the Mg1.5Al2O4.5: x% Eu3+ matches the single phase of face-centred cubic MgAl2O4. The estimated average crystallite sizes calculated using the XRD spectra were found to be in the order of 4 nm. The estimated crystal size was confirmed by the high-resolution transmission electron microscopy. The energy dispersive X-ray spectroscopy confirmed the presence of all expected elementary composition (Mg, Al, O and Eu). The field emission gun scanning electron microscope showed that varying the Eu3+ concentration influence the morphology of the prepared nanophosphor. The photoluminescence results showed that the host emits the violet colour at around 382 nm, which was attributed to the defects within the band gap ( Eg) of host material. The Eu3+-doped samples showed the emission at around 560, 580, 593, 618, 655 and 704 nm which are, respectively, attributed to the 5D1 → 7F3, 5D0 → 7F0, 5D0 → 7F1, 5D0 → 7F2, 5D0 → 7F3 and 5D0 → 7F4 characteristic transitions in Eu3+. The International Commission on Illumination colour chromaticity showed that the Eu3+ doping influences the emission colour.


2012 ◽  
Vol 512-515 ◽  
pp. 178-181
Author(s):  
Xiu Mei Han ◽  
Deng Hui Ren ◽  
Ying Ling Wang ◽  
Gui Fang Sun ◽  
Xi Wei Qi

MgLaLiSi2O7:Eu3+ phosphors have been prepared through the sol-gel process. X-ray diffraction (XRD), thermogravimetric and ddifferential thermal analysis (TG-DTA), FT-IR spectra and photoluminescence spectra were used to characterize the resulting phosphors. FT-IR spectra suggested that crystallized silicates have formed in the powders annealed at 1050°C. The results of XRD indicated that the phosphors crystallized completely at 1050°C. In MgLaLiSi2O7:Eu3+ phosphors, the Eu3+ shows its characteristic red (613nm, 5D0–7F2) emissions.


2012 ◽  
Vol 217-219 ◽  
pp. 733-736
Author(s):  
Xiu Mei Han ◽  
Shu Ai Hao ◽  
Ying Ling Wang ◽  
Gui Fang Sun ◽  
Xi Wei Qi

Zn2SiO4:Eu3+, Dy3+ phosphors have been prepared through the sol-gel process. X-ray diffraction (XRD), thermogravimetric and ddifferential thermal analysis (TG-DTA), FT-IR spectra and photoluminescence spectra were used to characterize the resulting phosphors. The results of XRD indicated that the phosphors crystallized completely at 1000oC. In Zn2SiO4:Eu3+,Dy3+ phosphors, the Eu3+ and Dy3+ show their characteristic red(613nm, 5D0-7F2), blue (481nm, 4F9/2–6H15/2) and yellow (577nm, 4F9/2–6H13/2) emissions.


2012 ◽  
Vol 545 ◽  
pp. 275-278 ◽  
Author(s):  
Lili Widarti Zainuddin ◽  
Norlida Kamarulzaman

A ceramics sample of LiTaO3 was prepared using a sol-gel method. The sample is annealed at 750 °C for 48 hours. X-ray diffraction analysis indicate the formation of single phase, rhombohedral structure. An ac impedance study was used to analyse the conductivity of LiTaO3 at room temperature and at various temperatures.


2011 ◽  
Vol 268-270 ◽  
pp. 356-359 ◽  
Author(s):  
Wen Song Lin ◽  
C. H. Wen ◽  
Liang He

Mn, Fe doped ZnO powders (Zn0.95-xMnxFe0.05O2, x≤0.05) were synthesized by an ameliorated sol-gel method, using Zn(CH3COO)2, Mn(CH3COO)2and FeCl2as the raw materials, with the addition of vitamin C as a kind of chemical reducer. The resulting powder was subsequently compacted under pressure of 10 MPa at the temperature of 873K in vacuum. The crystal structure and magnetic properties of Zn0.95-xMnxFe0.05O2powder and bulk samples have been investigated by X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). X-ray photoelectron spectroscopy (XPS) was used to study chemical valence of manganese, iron and zinc in the samples. The x-ray diffraction (XRD) results showed that Zn0.95-xMnxFe0.05O (x≤0.05) samples were single phase with the ZnO-like wurtzite structure. No secondary phase was found in the XRD spectrum. X-ray photoelectron spectroscopy (XPS) showed that Fe and Mn existed in Zn0.95-xMnxFe0.05O2samples in Fe2+and Mn2+states. The results of VSM experiment proved the room temperature ferromagnetic properties (RTFP) of Mn, Fe co-doped ZnO samples.


Nanopages ◽  
2019 ◽  
pp. 1-11
Author(s):  
G. M. Taha ◽  
M. N. Rashed ◽  
M. S. El-Sadek ◽  
M. A. Moghazy

Abstract BiFeO3 (BFO) nanopowder was synthesized in a pure form via a sol- gel method based on glycol gel reaction. Effect of drying and preheating temperature on preventing other phases was studied. Many parameters were studied as calcination temperature and time & stirring temperature as well. The prepared powder was characterized by X-Ray Diffraction of powder (XRD) and Transmission Electron Microscope (TEM). High pure BiFeO3 was obtained by preheated process at 400 °C for 0.5 h and calcination at 600 °C for 0.5 h without any impurities compared to dry at110 °C.


2011 ◽  
Vol 399-401 ◽  
pp. 1447-1450
Author(s):  
Zhi Yong Yu ◽  
Han Xing Liu

The layered LiNi1/2Mn1/2O2 cathode materials were synthesized by a sol gel method. The effects of calcination temperature and time on the structural and electrochemical properties of the LiNi1/2Mn1/2O2 were investigated. The prepared samples were characterized by X-ray diffraction (XRD) and electrochemical analysis. The results revealed that the layered LiNi1/2Mn1/2O2 material could be optimal synthesized at temperature of 900°C for 10h. The sample prepared under the above conditions has the highest initial discharge capacity of 151 mAh/g and showed no dramatic capacity fading during 20 cycles between 2.5-4.5V at a current rate of 20mA/g.


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