Up-Conversion Luminescence Properties of Ho3+ Doped and Yb3+/Ho3+ Co-Doped Y2WO6 Phosphors

2017 ◽  
Vol 727 ◽  
pp. 618-622 ◽  
Author(s):  
Xue Dong Gao ◽  
Deng Hui Xu ◽  
Yao Hui Zhu ◽  
Zai Fa Yang ◽  
Jiang Nan Du ◽  
...  
Keyword(s):  
High Temperature ◽  
Pump Power ◽  
Energy Level ◽  
Visible Region ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Doping ◽  
Two Photon ◽  
Photon Process ◽  
Co Doped

In this article, Ho3+ doped and Yb3+/ Ho3+ co-doped Y2WO6 phosphors were successfully prepared via high temperature solid method. Their structures were investigated with X-ray diffraction, the up-conversion (UC) excitation from a 980 nm diode laser, and the developed phosphor shown two UC emission bands in the visible region 540 and 643 nm. Based on the result, the intensity of the frequency up-conversion emission was enhanced significantly through co-doping with Yb3+ ions in the Y2WO6: Ho3+ phosphor. The dependence of emission intensity on the pump power indicated that the up-conversion emission was a two-photon process. At last, the energy level diagrams was discussed. The results show that Y2WO6 is a promising host material for UC phosphors.

Yellow-Orange Upconversion Luminescence in NaYF4:Er3+, Yb3+ Phosphor Synthesized by Microwave Combustion Method

2011 ◽  
Vol 295-297 ◽  
pp. 551-554 ◽  
Author(s):  
Jia Yue Sun ◽  
Chun Cao ◽  
Hai Yan Du
Keyword(s):  
Laser Excitation ◽  
Upconversion Luminescence ◽  
Green Emission ◽  
Combustion Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Two Photon ◽  
Yellow Orange ◽  
Photon Process ◽  
Microwave Combustion Method

Erbium and ytterbium co-doped sodium yttrium fluoride (NaYF4:Er3+,Yb3+) was synthesized by combusting in home microwave oven directly. The structure and morphology of the sample was characterized by the X-ray diffraction (XRD) and scanning electron microscopy (SEM), and its upconversion luminescence properties were investigated in detail. Under 980nm semiconductor laser excitation, the color of upconversion luminescence of NaYF4:Er3+,Yb3+ was green and red, and its upconversion spectrum exhibited distinct emission peaks at 522, 543 and 652 nm, the emission appears yellow-orange to the naked eye. The law of luminescence intensity versus pump power proved that the intense green emission at 522 and 543 nm were from Er3+(2H11/2→4I15/2and4S3/2→4I15/2), and the weaker red emission at 652 nm was from Er3+(4F9/2→4I15/2), which belong to the two photon process.

scholarly journals ENHANCED FERROELECTRICITY AND FERROMAGNETISM OF (Y, Ni) CO-DOPED BiFeO3 MATERIALS

2018 ◽  
Vol 56 (1A) ◽  
pp. 219
Author(s):  
Dao Viet Thang
Keyword(s):  
Ferroelectric Properties ◽  
Sol Gel ◽  
Rhombohedral Structure ◽  
Ferromagnetic Behavior ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Doping ◽  
Saturation Polarization ◽  
Perovskite Type ◽  
Co Doped

In this study, multiferroicMultiferroic Bi1-xYxFe0.975Ni0.025O3 (x = 0.00, 0.05, 0.10, and 0.15) called as (Y, Ni)                co-doped BiFeO3 materials were synthesized by a sol-gel method.  and characterized by X-ray diffraction diagrams and(XRD), energy-dispersive X-ray (EDX) and vibrating sample magnetization (VSM) measurements demonstrated. The result showed that Bi1-xYxFe0.975Ni0.025O3all investigated materials waspresent a single phase of the perovskite-type rhombohedral structure. Ferromagnetism and ferroelectricity of the Bi1-xYxFe0.975Ni0.025O3 materials have been investigated. Results showed that the co-doping by (Y, Ni) for (Bi, Fe)  have affected in enhancing by the (Y, Ni) co-doping, as a result the ferroelectric polarization and magnetization of BiFeO3. The magnetic characterization indicated that the ferromagnetic behavior wasthe initial BiFeO3 materialwere enhanced with increasing concentration of Y3+ for (Y, Ni) co-substituted of BiFeO3. Which could beion. It is attributed to the defferentdifference of the magnetic momentmoments of Ni2+ and Fe3+, and+ ions, as well as the Y3+-Fe3+,+ and Y3+-Ni2+ super-exchange interaction. Theinteractions. The characteristics of the investigated materials, such as remanent magnetization (Mr), saturation magnetization (Ms), remanent polarization (2Pr) and saturation polarization (2Ps) continuously increase upon increasing in the range of x from 0.00 to 0.15. When x = 0.15, the values of Mr and Ms are 0.078 and 0.794 emu/g, respectively. The values of 2Pr and 2Ps are 16.58 and 27.99 µC/cm2, respectively. Origin of ferromagnetic and ferroelectric properties of Bi1-xYxFe0.975Ni0.025O3 materials will be discussed in this paper.

Concentration-Dominated Temperature-Dependence of Upconversion Luminescence in Gd6WO12 Nanophosphor Co-Doped with Er3+ and Yb3+

2016 ◽  
Vol 16 (4) ◽  
pp. 3534-3541
Author(s):  
Yanqiu Zhang ◽  
Baojiu Chen ◽  
Xiangping Li ◽  
Jiashi Sun ◽  
Jinsu Zhang ◽  
...  
Keyword(s):  
Upconversion Luminescence ◽  
Thermal Quenching ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Two Photon ◽  
Microscopic Morphology ◽  
Co Precipitation ◽  
Co Doped ◽  
Scanning Electron

Nanosized Gd6WO12 phosphors containing various Er3+ concentrations and fixed Yb3+ concentration were synthesized by a co-precipitation method. The crystal structure and microscopic morphology of the obtained nanophosphors were characterized by means of X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). Two-photon processes for both the green and red upconversion (UC) emissions were confirmed by analyzing the dependence of UC intensities on 980 nm laser working current. UC emission intensity changing with temperature displays different trends for the samples with different Er3+ concentrations. The experimental results indicated that thermal quenching behavior of UC luminescence could not be simply explained by crossover mechanism. The enhancement for green UC emission in the sample with higher Er3+ concentration was discussed. Finally, the Er3+ concentration dependence of UC luminescence was experimentally observed, and its mechanisms were analyzed.

STRUCTURE AND MAGNETIC PROPERTIES OF Co-DOPED SnO2 NANOWIRES

2011 ◽  
Vol 10 (04n05) ◽  
pp. 967-971 ◽  
Author(s):  
U. K. GOUTAM ◽  
SHASHWATI SEN ◽  
JAGANNATH ◽  
A. K. SINGH ◽  
R. MUKUND ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Magnetic Measurements ◽  
Ferromagnetic Behavior ◽  
Tubular Furnace ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Doping ◽  
Sno2 Nanowires ◽  
Tin Metal ◽  
Co Doped

Co -doped SnO2 nanowires were grown by thermal evaporation of a mixture of Tin metal powder and CoCl2 · 6H2O in a tubular furnace. The growth occurs by vapor–solid growth mechanism. Nanowires grew along the sidewall of the alumina boat placed in the tubular furnace and the diameter of these nanowires (as was evident from scanning electron microscopy), was found to be in the range of 50 nm to 200 nm. Co was successfully doped in SnO2 lattice as revealed by X-ray diffraction data and was found to be in Co2+ state in the nanowires as detected by X-ray Photoelectron Spectroscopy measurements. Room temperature magnetic measurements, carried out using Vibrating Sample Magnetometer, indicated ferromagnetic behavior of the nanowires indicating their potential for spintronics applications. With increasing Co doping (upto 1%), the lattice parameters of SnO2 decreased and the saturation magnetization increased, suggesting a strong structure-magnetic property relationship.

Effect of N and P codoping on ZnO properties

2013 ◽  
Vol 645 ◽  
pp. 64-67 ◽  
Author(s):  
Jin Zhong Wang ◽  
Elangovan Elamurugu ◽  
Hong Tao Li ◽  
Shu Jie Jiao ◽  
Lian Cheng Zhao ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Atomic Ratio ◽  
Zno Films ◽  
X Ray Diffraction ◽  
Nitrogen And Phosphorus ◽  
X Ray ◽  
Co Doping ◽  
Glass Substrates ◽  
Doped Zno ◽  
Co Doped

Nitrogen and Phosphorus co-doped (N+P)- zinc oxide (ZnO) films were RF sputtered on corning glass substrates at 350 °C and comparatively studied with undoped, N-, and P- doped ZnO. X-ray diffraction spectra confirmed that the ZnO structure with a preferred orientation along direction. Scanning electron microscope analysis showed different microstructure for the N+P co-doping, and thus probably confirming the co-existence of both the dopants. X-ray photoelectron spectroscopy spectra revealed that the chemical composition in N+P co-doped ZnO are different from that found in undoped, N-, and P- doped ZnO. The atomic ratio of N and P in N+P co-doped ZnO is higher than that in single N or P doped ZnO. One broad ZnO emission peak around 420 nm is observed in photoluminescence spectra. The relative intensity of the strongest peak obtained from co-doped ZnO films is about twice than the P- doped and thrice than the pure and N- doped films.

Effect of HPHT processing on the structure, and thermoelectric properties of Co4Sb12 co-doped with Te and Sn

2015 ◽  
Vol 3 (8) ◽  
pp. 4637-4641 ◽  
Author(s):  
Hairui Sun ◽  
Xiaopeng Jia ◽  
Le Deng ◽  
Pin Lv ◽  
Xin Guo ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Thermoelectric Properties ◽  
Polycrystalline Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Method ◽  
Co Doped

Te–Sn co-doped Co4Sb12 bulk polycrystalline materials Co4Sb11.7−xTexSn0.3 have been prepared using a high pressure and high temperature method and then characterized using X-ray diffraction.

Effects of Fe and Ni Co-Doping on the Optical Properties of TiO2 Thin Films

2019 ◽  
Vol 19 (01) ◽  
pp. 1850046
Author(s):  
Mahboubeh Yeganeh ◽  
Maliheh Mousavi
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Oxygen Vacancies ◽  
Visible Region ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Tio2 Thin Films ◽  
X Ray ◽  
Co Doping ◽  
Uv Visible

In this work, the effects of Fe/Ni co-doping on structural and optical properties of TiO2 thin films were investigated by the X-ray diffraction, scanning electron microscope and UV-visible spectroscopy. The optical properties of transmittance, extinction coefficient, refractive index, real and imaginary parts of dielectric constant of the thin films, prepared by spray pyrolysis, revealed that the absorption in visible region increases due to the influence of Fe/Ni co-doping. The widening of the gap energies is observed as a result of doping. The increased optical gap as a consequence of doping can be explained by decreasing the size of nanoparticles, as confirmed by SEM and increasing the formation of oxygen vacancies as a result of Ni[Formula: see text] substitution to Ti[Formula: see text] and appearance of the Burstein–Moss effect.

Upconversion Luminescence and Temperature Sensing of InNbO4:Er3+/Yb3+ Phosphors

2021 ◽  
Vol 13 (4) ◽  
pp. 563-568
Author(s):  
Xingbang Dong ◽  
Huanjun Zhang ◽  
Yi Li ◽  
Zheng Wang ◽  
Yang Yang ◽  
...  
Keyword(s):  
Upconversion Luminescence ◽  
Solid State Reaction Method ◽  
Temperature Sensing ◽  
Fluorescence Intensity Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Doping ◽  
Two Photon ◽  
Maximum Value ◽  
Optical Thermometry

Er3+/Yb3+ co-doped InNbO4 phosphors were synthesized using solid state reaction method. Crystal structure was characterized using X-ray diffraction (XRD), which confirm all obtained phosphors had a monoclinic-wolframite structure and no impurity phase was introduced upon doping. Upon 980 nm excitation, upconversion (UC) emission from Er3+ ions was observed in green and red range. UC emission was obviously enhanced after co-doping Yb3+ ions and reached the maximum for 10 mol% Yb3+ ions. The relation between emission intensity and pump power was performed, revealing that the UC emission result from two-photon processes. Optical temperature sensing property was investigated by exploiting fluorescence intensity ratio (FIR) between 2H11/2 and 4S3/2 levels of Er3+ ions. Its maximum value of absolute sensitivity obtained was 0.0091 K-1, suggesting InNbO4:Er3+/Yb3+ phosphors show potential application in optical thermometry.

Silver Co-Doping Effect on the Antimony Doped Tin Dioxide Electrode

2013 ◽  
Vol 734-737 ◽  
pp. 2382-2385
Author(s):  
Yun Hai Wang ◽  
Yong Rong Liang ◽  
Guo Li
Keyword(s):  
Electron Microscopy ◽  
Tin Dioxide ◽  
Dip Coating ◽  
X Ray Diffraction ◽  
Silver Doping ◽  
X Ray ◽  
Co Doping ◽  
Pyrolysis Method ◽  
Co Doped ◽  
Scanning Electron

In the present research, silver antimony co-doped tin dioxide electrodes were prepared via dip-coating pyrolysis method. The effect of silver doping on the composition, morphology, crystallization and electrochemical properties was investigated through various techniques such as scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDX) and cyclic voltammetry. The results showed that with proper silver doping, the electrode activity for wastewater treatment may be enhanced.

Effects of Sn2+ Co-Doping on the Photoluminescence of Eu3+ Ion in Strontium Phosphate

2006 ◽  
Vol 317-318 ◽  
pp. 803-806 ◽  
Author(s):  
Chung Hsin Lu ◽  
V. Natarajan
Keyword(s):  
Ultra Violet ◽  
Solid State Reaction Method ◽  
Host Lattice ◽  
X Ray Diffraction ◽  
Phosphor Material ◽  
X Ray ◽  
Co Doping ◽  
Reducing Atmosphere ◽  
Strontium Phosphate ◽  
Co Doped

The emission of Sn2+ ion can vary from blue to red depending on its co-ordination number in the host lattice. Since Sn2+ ion has strong absorption in the ultra-violet region and can act as a reducing agent, it is of interest to examine the effects of co-doping Sn2+ ions on the luminescence properties of Eu3+ ions in different inorganic phosphor materials. In the present work, Eu3+ and Sn2+ ions co-doped strontium phosphate phosphors were synthesized via a solid-state reaction method in air, argon and reducing atmosphere. The prepared samples were characterized via X-ray diffraction. It was observed that the prepared Eu3+-doped strontium phosphate phosphor material had enhanced Eu3+ emission upon excitation with 395 nm light.

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