13494-98-9Relevant articles and documents
Auto-ignition based synthesis of Y2O3 for photo- and thermo-luminescent applications
Hari Krishna,Nagabhushana,Nagabhushana,Chakradhar,Sivaramakrishna,Shivakumara,Thomas, Tiju
, p. 129 - 137 (2014)
We present a simple route for synthesis of Y2O3 for both photoluminescent (PL) and thermoluminescent (TL) applications. We show that by simply switching the fuel from ethylene di-amine tetracetic acid (EDTA) to its disodium derivative (Na2-EDTA), we obtain a better photoluminescent material. On the other hand, use of EDTA aids in formation of Y2O3 which is a better thermoluminescent material. In both cases pure cubic nano-Y2O3 is obtained. For both the material systems, structural characterization, photoluminescence, thermoluminescence, and absorbance spectra are reported and analyzed. Use of EDTA results in nano Y2O3 with crystallite size ～10 nm. Crystallinity improves, and crystallite size is larger (～30 nm) when Na2-EDTA is used. TL response of Y2O3 nanophosphors prepared by both fuels is examined using UV radiation. Samples prepared with EDTA show well resolved glow curve at 140 C, while samples prepared with Na2-EDTA shows a glow curve at 155 C. Effect of UV exposure time on TL characteristics is investigated. The TL kinetic parameters are also calculated using glow curve shape method. Results indicate that the TL behavior of both the samples follow a second order kinetic model.
Synthesis and luminescence properties of Y2O3:Eu with flower-like microstructure
Zhang, Xuemei,Wang, Jiao,Guo, Kai,Chen, Haohong,Yang, Xinxin,Zhao, Jingtai
, p. 149 - 156 (2012)
Europium-doped yttrium hydroxide (Y(OH)3:Eu) with flower-like microstructure has been successfully prepared via a facile hydrothermal process, using potassium sodium tartrate (C4H4O6KNa) as a structure-directing reagent. Europium-doped yttrium oxide (Y 2O3:Eu) with similar morphology is prepared by calcining the as-prepared Y(OH)3:Eu at 700 °C for 4 h. Influencing factors such as the concentration of potassium sodium tartrate, the amount of sodium hydroxide, and the temperature used for hydrothermal synthesis are systematically investigated. Possible formation mechanism for the flower-like microstructure is proposed on the basis of time-dependent experiment. Y 2O3:Eu samples show a strong red emission corresponding to the 5D0-7F2 transition of Eu 3+ ions under excitation. Emission intensity varies between samples with different morphologies. The optimum Eu3+ doping concentration is also explored. This work sheds some light on the design and preparation of novel microstructures.
Spin-phonon coupling in multiferroic Y2CoMnO6
Silva, Rosivaldo X.,Castro Júnior, Manoel C.,Yá?ez-Vilar, Susana,Andújar, Manuel Sánchez,Mira, Jorge,Se?arís-Rodríguez, María Antonia,Paschoal, Carlos William A.
, p. 909 - 915 (2017)
Spin-phonon coupling in rare-earth based manganites with double perovskite structure plays a crucial role in the magnetoelectric properties of these ferromagnetic materials. Particularly, on Y2CoMnO6(YCMO), it is assumed that spin-phonon coupling is related to the induced ferroelectric polarization. This confers to YCMO a multiferroic characteristic. In this work, we probed the spin-phonon coupling in YCMO by temperature-dependent Raman spectroscopy measurements in ceramic samples obtained by the nitrate decomposition method. Raman scattering revealed some anomalies that could be attributed to a weak spin-phonon coupling, an unconventional behavior for rare-earth based manganites with double perovskite structure, in which the coupling does not fit with the quadratic magnetization.
Studies on terbium doped apatite phosphors prepared by precipitation under microwave conditions
Muresan,Perhaita,Prodan,Borodi
, p. 135 - 146 (2018)
In this study we present our first attempts to obtain silicate apatite phosphors by precipitation with NaOH under microwave conditions. Y and La precursors fired at different temperatures (800 °C÷1400 °C) led to phosphors with hexagonal apatite structure
Preparation and photoluminescence properties of SrY2O4:Yb3+, Er3+ powders
Yang, Jikai,Xiao, Siguo,Ding, Jianwen,Yang, Xiaoliang,Wang, Xiangfu
, p. 424 - 427 (2009)
Yb3+/Er3+ co-doped SrY2O4 powders are prepared by developing a nitric-decomposition method. Under 980 nm laser excitation, the green and red up-conversion emissions are observed at around 549 and 661 nm, which a
The energy transfer phenomena and colour tunability in Y2O 2S:Eu3+/Dy3+ micro-fibers for white emission in solid state lighting applications
Som,Mitra,Kumar, Vijay,Kumar, Vinod,Terblans,Swart,Sharma
, p. 9860 - 9871 (2014)
This paper reports on the structural, optical and photometric characterization of an Eu3+/Dy3+ doped yttrium oxysulfide phosphor (Y2O2S:Eu3+/Dy3+) for near white emission in solid state lighting. A series of Y2O2S phosphors doped with Eu3+/Dy3+ were prepared by the hydrothermal method. The microstructures of the as-synthesized phosphors were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The XRD results reveal that the obtained powder phosphors have a single-phase hexagonal structure and also indicate that the incorporation of the dopants/co-dopants did not affect the crystal structure. The SEM images reveal the morphology of the prepared phosphors as an intense interpenetrating network of interconnected micro-fibers with a diameter of about 0.15 μm. The band gap of the phosphors was calculated from diffuse reflectance spectra using the Kubelka-Munk function. The Eu3+, Dy3+ doped and Eu 3+/Dy3+ co-doped phosphors illuminated with ultraviolet light showed characteristic red luminescence corresponding to the 5D0→7FJ transitions of Eu 3+ and characteristic blue and yellow luminescence corresponding to the 4F9/2→6H15/2 or 4F9/2→6H13/2 transitions of Dy3+. The luminescence spectra, the energy transfer efficiency and the decay curves of the phosphors indicated that there exists a strong energy transfer from Dy3+ to Eu3+ and this was demonstrated to be a resonant type via a dipole-quadrupole reaction. Furthermore, the critical distance of the Eu3+ and Dy3+ ions have also been calculated. By utilizing the principle of energy transfer it was also demonstrated that with an appropriate tuning of the activator content the Y 2O2S:Eu3+/Dy3+ phosphors can exhibit a great potential to act as single-emitting component phosphors for white light emission in solid state lighting technology.
Soft-chemical synthesis and tunable luminescence of Tb3+, Tm3+/Dy3+-doped SrY2O4 phosphors for field emission displays
Zhang, Yang,Geng, Dongling,Shang, Mengmeng,Zhang, Xiao,Li, Xuejiao,Cheng, Ziyong,Lian, Hongzhou,Lin, Jun
, p. 4799 - 4808 (2013)
Tb3+, Tm3+, and Dy3+-activated SrY 2O4 phosphors have been prepared via Pechini-type sol-gel method. X-Ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), photoluminescence (PL) and lifetimes, as well as cathodoluminescence (CL) spectra were used to characterize the samples. Under low-voltage electron beam excitation, the Tb 3+-doped samples show a green luminescence, with a better CIE coordinates and higher emission intensity than the commercial product ZnO: Zn. Blue and yellow emissions could be obtained by doping with Tm3+ and Dy3+, respectively. A color-tunable emission in SrY2O 4 phosphors can be realized by co-doping with Tm3+ and Dy3+. White cathodoluminescence (CL) has been realized in a single-phase SrY2O4 host by co-doping with Tm3+ and Dy3+ for the first time with CIE (0.315, 0.333). Furthermore, the cathodoluminescence (CL) properties of SrY2O4: Tb 3+/Tm3+/Dy3+ phosphors including the dependence of CL intensity on accelerating voltage and filament current, the decay behaviour of CL intensity under electron bombardment, and the stability of CIE chromaticity coordinate have been investigated in detail. The as-prepared phosphors might be promising for use in field-emission display (FED) devices.
The sonochemical and microwave-assisted synthesis of nanosized YAG particles
Letichevsky, Yana,Sominski, Lena,Moreno, Jose Calderon,Gedanken, Aharon
, p. 1445 - 1449 (2005)
Nanoparticles of YAG were prepared by sonochemistry and by microwave radiation. In both cases, the last stage of the preparation was annealing at a high temperature, which led to a highly aggregated product. To reduce the aggregation we have added κ-carrageenan (a sugar) to the reaction mixture. The effect of the sugar is presented and discussed herein. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2005.
Sol-gel synthesis and photoluminescence of K2NiF4-type structure phosphors CaxSr1-xGdyY1-yAlO 4:zEu3+ with hybrid precursors
Wu, Junjie,Yan, Bing
, p. 214 - 218 (2007)
CaxSr1-xGdyY1-yAlO 4:zEu3+ (x = 0.2-1.0, y = 0-1.0, z = 0.01-0.07) was synthesized by a hybrid precursor assembly sol-gel technology. We got sol solutions by stoichiometric rare earth nitrate, Sr(NO3)2, Ca(NO3)2, Al(NO3)3, at the same time investigated the relationship between the sol formed and experiment variable including Ph, temperature, concentration, and so on. Through drying and calcining precursors, we got luminescent materials powder. The particle size of luminescent materials is about 40 nm characterized by XRD and having thick three-dimension grains as SEM shown. Not only co-doping Ca2+ and Sr2+ but also changing the ratio of Gd3+ and Y3+ cannot change the crystalline structure in CaxSr1-xGdyY1-yAlO 4, it also formed the crystalline structure as that of pure-phase CaGdAlO4. All these photoluminescence materials show good emission spectra and their luminescent intensity depend on the concentrating of Eu3+: in all these luminescent materials, there exist emission come from Eu3+ activator' transitions of 5D0-7FJ (J = 0-3) and their emission intensity increase as adding to the concentration of Eu3+.
Synthesis of nanocrystalline YFeO3 and its magnetic properties
Maiti, Ramaprasad,Basu, Soumen,Chakravorty, Dipankar
, p. 3274 - 3277 (2009)
Single phase nanocrystalline YFeO3 has been synthesized by a simple solution method. The average particle diameter is 42.2 nm. The particles exhibit ferromagnetic behaviour in the temperature range 10-300 K with a coercivity of 23 kOe. The magn
