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.

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.

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.

scholarly journals Intensive up-conversion photoluminescence of Er3+-doped Bi7Ti4NbO21 ferroelectric ceramics and its temperature sensing

2014 ◽  
Vol 04 (04) ◽  
pp. 1450028 ◽  
Author(s):  
Hua Zou ◽  
Jun Li ◽  
Qiufeng Cao ◽  
Xusheng Wang ◽  
Xinwei Hui ◽  
...  
Keyword(s):  
Single Phase ◽  
Temperature Sensing ◽  
Ferroelectric Ceramics ◽  
Fluorescence Intensity Ratio ◽  
X Ray Diffraction ◽  
Conventional Solid State Reaction ◽  
Er Doping ◽  
Optical Thermometry ◽  
Bio Imaging ◽  
Fir Technique

The intensive up-conversion (UC) photoluminescence and temperature sensing behavior of Er 3+-doped Bi 7 Ti 4 NbO 21( BTN ) ferroelectric ceramics prepared by a conventional solid-state reaction technique have been investigated. The X-ray diffraction and field emission scanning electron microscope analyses demonstrated that the Er 3+-doped BTN ceramics are single phase and uniform flake-like structure. With the Er 3+ ions doping, the intensive UC emission was observed without obviously changing the properties of ferroelectric. The optimal emission intensity was obtained when Er doping level was 15 mol.%. The temperature sensing behavior was studied by fluorescence intensity ratio (FIR) technique of two green UC emission bands, and the experimental data fitted very well with the function of temperature in a range of 133–573 K. It suggested that the Er 3+-doped BTN ferroelectric ceramics are very good candidates for applications such as optical thermometry, electro-optical devices and bio-imaging ceramics.

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.

scholarly journals Structure, Dielectric and Multiferroic Properties of Bi0.85Nd0.15Fe0.98Zr0.02O3 in Ba and Ti Co-Doping

2021 ◽  
Author(s):  
Lizhu Zeng ◽  
Yuming Lu ◽  
Lujia Zhang ◽  
Xin Gong ◽  
Jianfeng Tang ◽  
...  
Keyword(s):  
Room Temperature ◽  
Oxygen Vacancies ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Conventional Solid State Reaction ◽  
Structure Transition ◽  
X Ray ◽  
Co Doping ◽  
Average Grain Size ◽  
Rhombohedral Perovskite Structure

Abstract Multiferroic (1- x)Bi0.85Nd0.15Fe0.98Zr0.02O3- xBaTiO3 (x = 0, 0.275, 0.3, 0.325, 0.35, 0.375, 0.4) ceramics were synthesized by the conventional solid state reaction method. X-ray diffraction studies confirm the phase transition from rhombohedral perovskite structure to pseudocubic structure with the introduction of BaTiO3. The results of the refinement indicate the BaTiO3 is successfully doped into the crystal lattice. The microstructure analysis shows that the average grain size increases with the introduction of BaTiO3. An increase in remanant polarization has been achieved at room temperature as the BaTiO3 concentration increasing. A greatly reduced leakage current density of about two orders of magnitude is observed in x = 0.375 (J = 2.4×10− 7 A/cm2) ceramic. The dielectric properties have been enhanced by the addition of BaTiO3, which is attributed to the reduction in Fe2+ ions and oxygen vacancies. Due to the grain effect and structure transition caused by the doping of BaTiO3, the magnetization reveals a slight decrease while the coercive field for x = 0.325 (Hc = 1785.8 Oe) increases to 6.4 times of the undoped ceramic.

Studies of Microstructure and Electro-Magnetic Transport Property of La0.67Ca0.33MnO3 Ceramic

2017 ◽  
Vol 373 ◽  
pp. 205-208
Author(s):  
Shou Lei Xu ◽  
Er Juan Xie ◽  
Xiu Qing Cao ◽  
Yu Yang Huang ◽  
Ding Kang Xiong ◽  
...  
Keyword(s):  
Transition Temperature ◽  
Positron Lifetime ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Metal Insulator ◽  
X Ray ◽  
Maximum Value ◽  
The Mean ◽  
Magnetic Transport ◽  
Electro Magnetic

The positron annihilation techniques and X-ray diffraction have been used to study the microstructure of the La0.67Ca0.33MnO3 ceramics prepared by the solid-state reaction method at different sintered temperatures (T=1573K, 1623K, 1673K, 1723K, 1773K, 1823K). And the electro-magnetic transport behavior of the samples was measured by VSM and Resistivity modular on PPMS. According to these results, all samples show a perovskite structure, the ferromagnetic-paramagnetic and metal-insulator transitions occur at the transition temperature Tc and TMI, respectively, which is almost the same. For La0.67Ca0.33MnO3 sintered at 1673K, the mean positron lifetime is the largest, the maximum value of the magnetization is achieved on the magnetization-temperature curve at H=0.2mT, while the transition temperature occurs at about 244K.

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.

Yellow Upconversion Luminescence in Ho3+/Yb3+ Co-Doped La2(WO4)3 Phosphor

2013 ◽  
Vol 401-403 ◽  
pp. 758-761 ◽  
Author(s):  
Jia Yue Sun ◽  
Bing Xue ◽  
Guang Chao Sun ◽  
Dian Peng Cui
Keyword(s):  
Light Emission ◽  
Upconversion Luminescence ◽  
Solid State Reaction Method ◽  
Excitation Power ◽  
Yellow Emission ◽  
Excitation Power Density ◽  
X Ray Diffraction ◽  
Two Photon ◽  
Photon Process ◽  
Co Doped

The strong yellow upconversion (UC) light emission has been observed in Ho3+/Yb3+ co-doped La2(WO4)3 phosphor under the excitation of 980 nm diode laser. The phosphors were synthesized by the traditional solid-state reaction method. The phrase structures of the samples were characterized by X-ray diffraction (XRD). The doping concentration of Yb3+ was determined to be 20mol% for the strongest yellow emission. Then, the dependence of UC emission intensity on excitation power density showed that the green and red UC emissions are involved in two-photon process. The possible UC mechanisms for the strong yellow emission were also investigated.

scholarly journals Enhanced electrical conductivity in Zr-Doped (La0.7Ba0.3)(Mn0.5Fe0.5)O3 solid solutions

2020 ◽  
Vol 10 (06) ◽  
pp. 2050032
Author(s):  
Yogesh Kumar ◽  
Jaswinder Pal ◽  
Parambir Singh Malhi ◽  
Rakesh Kumar
Keyword(s):  
Electrical Conductivity ◽  
Solid Solutions ◽  
Ac Conductivity ◽  
Small Polaron ◽  
Negative Temperature ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Maximum Value ◽  
Jonscher’S Power Law

The perovskite ([Formula: see text][Formula: see text]([Formula: see text][Formula: see text][Formula: see text]O3, where [Formula: see text] = 0.1, 0.2 and 0.3, ceramics were synthesized by solid-state reaction method. The introductory structural studies were followed through by X-ray diffraction technique and the results have disclosed that all the samples were crystallized into an isolated phase. The Zr substitution in the resulting solid solutions increases the electrical conductivity and the maximum value of ac conductivity has been found to be [Formula: see text]118.8 S [Formula: see text] cm[Formula: see text] for [Formula: see text] = 0.3 at 200[Formula: see text]C (at 1 MHz). The frequency dependence of ac conductivity data follows Jonscher’s power law. The variation of the exponent [Formula: see text] versus temperature follows the nonoverlapping small polaron tunneling (NSPT) model. The dielectric relaxation has been observed to be of non-Debye nature for all measuring temperatures (50–200[Formula: see text]C). The impedance spectroscopy reveals that all the samples exhibit negative temperature coefficient of resistance (NTCR) behavior. The prepared samples (for [Formula: see text] > 1) are supposed to be suitable for cathode materials in SOFCs.

scholarly journals Mining Wastes of an Albite Deposit as Raw Materials for Vitrified Mullite Ceramics

Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 232
Author(s):  
Pedro J. Sánchez-Soto ◽  
Eduardo Garzón ◽  
Luis Pérez-Villarejo ◽  
George N. Angelopoulos ◽  
Dolores Eliche-Quesada
Keyword(s):  
Particle Size ◽  
Raw Materials ◽  
Phase Evolution ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Mining Wastes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Maximum Value

In this work, an examination of mining wastes of an albite deposit in south Spain was carried out using X-ray Fluorescence (XRF), X-ray diffraction (XRD), particle size analysis, thermo-dilatometry and Differential Thermal Analysis (DTA) and Thermogravimetric (TG) analysis, followed by the determination of the main ceramic properties. The albite content in two selected samples was high (65–40 wt. %), accompanied by quartz (25–40 wt. %) and other minor minerals identified by XRD, mainly kaolinite, in agreement with the high content of silica and alumina determined by XRF. The content of Na2O was in the range 5.44–3.09 wt. %, being associated with albite. The iron content was very low (<0.75 wt. %). The kaolinite content in the waste was estimated from ~8 to 32 wt. %. The particle size analysis indicated values of 11–31 wt. % of particles <63 µm. The ceramic properties of fired samples (1000–1350 °C) showed progressive shrinkage by the thermal effect, with water absorption and open porosity almost at zero at 1200–1250 °C. At 1200 °C, the bulk density reached a maximum value of 2.38 g/cm3. An abrupt change in the phase evolution by XRD was found from 1150 to 1200 °C, with the disappearance of albite by melting in accordance with the predictions of the phase diagram SiO2-Al2O3-Na2O and the system albite-quartz. These fired materials contained as main crystalline phases quartz and mullite. Quartz was present in the raw samples and mullite was formed by decomposition of kaolinite. The observation of mullite forming needle-shape crystals was revealed by Scanning Electron Microscopy (SEM). The formation of fully densified and vitrified mullite materials by firing treatments was demonstrated.

Sign in / Sign up

Export Citation Format

Share Document