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.
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.
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
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.
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+.
Controllable preparation and fluorescence properties of Y3+ and Eu3+ co-doped mesoporous silica
Zhang, Chao,Guang, Shanyi,Xu, Hongyao
, p. 1409 - 1415 (2010)
The controllable preparation and forming mechanism of rare-earth Y3+ and Eu3+ chemically co-doped fluorescent mesoporous silica were studied in detail. Their structures, morphologies, chemical compositions and emission properties were characterized and evaluated by small angle X-ray scattering, nitrogen adsorption/desorption measurements, high resolution transmission electron microscopy, inductive coupled plasma-atomic emission, X-ray photoelectron spectra and fluorescent spectroscopy. The results show that chemical composition of the resultant mesoporous materials were significantly affected by solution acidity condition, and can be effectively adjusted by varying the feed ratio of raw materials at a suitable solution acidity condition. These materials with a well-ordered two-dimensional hexagonal mesoporous structure and high specific surface area exhibit significantly broadened emission band from 526 to 682 nm and the fluorescent emission mechanism and influence of materials structure on optical properties were investigated.
Morphology formation mechanism and fluorescence properties of nano-phosphor YPO4:Sm3+ excited by near-ultraviolet light
Wu, Jinxiu,Li, Mei,Jia, Huiling,Liu, Zhaogang,Jia, Hengjun,Wang, Zhongzhi
, (2020)
A series of YPO4:Sm3+ phosphors were prepared by the hydrothermal method. The composition, structure, morphology and luminescence properties of the samples were characterized and analyzed by means of X-ray diffractometer (XRD), scanning electron microscopy (SEM and EDS) and fluorescence spectrophotometer (FL). The morphology formation mechanism and fluorescence temperature characteristic of nano-phosphor YPO4:Sm3+ were mainly studied. The results show that the products are single tetragonal phosphor yttrium ore structure with nanosphere morphology. Morphology formation mechanism of YPO4:Sm3+ is nucleation - dissolution - recrystallization - crystal growth. The strongest excitation spectrum appears at 404 nm, which belongs to the 6H5/2 → 4F7/2 transition of Sm3+. The strongest emission spectrum appears at 603 nm, which belongs to the 4G5/2 → 6H7/2 transition of Sm3+. The chromaticity coordinates show that the phosphors are red. The optimum doping concentration of activator Sm3+ in YPO4 matrix is 2%. When the doping concentration of Sm3+ is higher than 2%, concentration quenching occurs. The mechanism of concentration quenching is electric dipole - electric dipole interaction. The critical distance for energy transfer between Sm3+ is 1.899 nm. Nano-phosphor YPO4:2% Sm3+ has good thermal stability, and its fluorescence lifetime is 217.99 μs. The activation energy of thermal quenching is 0.2566 eV.
Color-tunable luminescence of Y4Si2N 2O7:Ce3+, Tb3+, Dy3+ Phosphors prepared by the soft-chemical ammonolysis method
Geng, Dongling,Li, Kai,Lian, Hongzhou,Shang, Mengmeng,Zhang, Yang,Wu, Zhijian,Lin, Jun
, p. 1955 - 1964 (2014)
Ce3+-, Tb3+-, and Dy3+-activated Y 4Si2N2O7 phosphors have been prepared by the Pechini-type sol-gel method followed by ammonolysis of the precursors. The phase purity, morphology, crystallization condition, chemical composition, and thermal stability of the products have been studied carefully by X-ray diffraction (XRD), energy-dispersive X-ray (EDX), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), fourier-transform infrared (FTIR), and thermogravimetry analysis (TGA) techniques. The photoluminescence (PL) and cathodoluminescence (CL) properties of Ce3+-, Tb3+-, and Dy3+-doped Y 4Si2N2O7 phosphors were also investigated. The electronic structure of Y4Si2N 2O7 has been investigated by density-functional theory methods. The calculations revealed that the nitrogen atom contributes more excited electrons than the O atom. The band gap has been calculated through the reflection spectrum of the Y4Si2N2O7 host. For Ce3+/Tb3+/Dy3+ singly doped Y 4Si2N2O7 products, the phosphors give the typical emissions of the activators. The energy transfers from Ce 3+ to Tb3+ and Dy3+ ions have been found and demonstrated through the PL spectra and luminescence decay times. The emission color of Y4Si2N2O7:Ce3+, Tb3+ and Y4Si2N2O 7:Ce3+, Dy3+ samples can be tuned by energy transfer processes. Additionally, the temperature-dependent PL properties and the degradation property of CL under continuous electron bombardment of the as-synthesized phosphors prove that the Y4Si2N 2O7 host has good stability. Therefore, the Y 4Si2N2O7:Ce3+, Tb 3+, Dy3+ phosphors could serve as a promising candidate for UV W-LEDs and FEDs. Copyright
Photoluminescent properties of Eu3+, Tb3+ activated M3Ln(PO4)3 (M = Sr, Ca; Ln = Y, La, Gd) phosphors derived from hybrid precursors
Xiao, Xiuzhen,Xu, Shuai,Yan, Bing
, p. 255 - 259 (2007)
Ternary orthophosphates M3Ln(PO4)3 doped with Eu3+, Tb3+ were prepared via an in situ chemical co-precipitation technology, and the assembly process of hybrid precursors were as follows: using rare-earth coordination polymers with salicylic acid as precursors and composing with the polyvinyl alcohol (PVA) as dispersing media. Their microstructure and micromorphology have been analyzed by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The emission spectra exhibited strong luminescence of 5D0 → 7F2 at 609 nm, indicating that the Eu3+ located in a noncentrosymmetric position in Eu-doped M3Ln (PO4)3 matrix. Besides this, the values of red to orange emission intensities for Eu3+ in Sr3Gd (PO4)3 strongly depend on the doping concentration.
New rare earth langbeinite phosphosilicates KBaREEZrP2SiO12 (REE: La, Nd, Sm, Eu, Gd, Dy) for lanthanide comprising nuclear waste storage
Kumar, Sathasivam Pratheep,Gopal, Buvaneswari
, p. 422 - 429 (2016)
In contrast to the existing cubic langbeinite phosphates and sulphates, orthorhombic langbeinite phosphosilicates of the chemical formula KBaYMP2SiO12 (M: Zr, Sn), KBaREEZrP2SiO12 (REE: La, Nd, Sm, Eu, Gd, Dy) and the wasteform KBaY0.6La0.1Nd0.1Sm0.1Eu0.1ZrP2SiO12 have been synthesized by solution method. Powder X-ray diffraction analysis affirmed that the compounds were phase pure and crystallized in an orthorhombic structure with P212121 space group. Spectral analysis of the wasteform revealed the phase stability, thermal stability and chemical durability of the langbeinite structure. Chemical durability of the powder wasteform has been studied by a dynamic Soxhlet test. Elemental analysis of the leachates showed that the normalized mass losses of barium, zirconium and silicon were in the order of 10-3-10-2 g/m2, 10-5-10-4 g/m2 and 10-2-10-1 g/m2 respectively. Normalized mass losses of lanthanides, potassium and phosphorous were found to be below the instrumental detection limits.
Microstructure evolution in two-step-sintering process toward transparent Ce:(Y,Gd)3(Ga,Al)5O12 scintillation ceramics
Beitlerová, Alena,Chen, Haohong,Chen, Xiaopu,Feng, Yagang,Kou, Huamin,Ku?erková, Romana,Li, Jiang,Li, Xiaoying,Liu, Xin,Mihóková, Eva,Nikl, Martin,Xie, Tengfei
, (2020)
Scintillators are broadly utilized in high energy particle detection and medical imaging. Ce:(Y,Gd)3(Ga,Al)5O12 ceramics has recently demonstrated excellent scintillation properties and great commercialization potential. T
Highly uniform α-NaYF4:Yb/Er hollow microspheres and their application as drug carrier
Han, Yunhua,Gai, Shili,Ma, Ping'An,Wang, Liuzhen,Zhang, Milin,Huang, Shaohua,Yang, Piaoping
, p. 9184 - 9191 (2013)
Highly uniform α-NaYF4:Yb/Er hollow microspheres have been successfully prepared via a simple two-step route. First, the core-shell structured MF@Y(OH)CO3:Yb/Er precursor was fabricated by a urea-based homogeneous precipitation method using colloidal melamine formaldehyde (MF) microspheres as template. Then the Y(OH)CO3:Yb/Er precursor was transformed into hollow NaYF4:Yb/Er (α and β mixed phase) by a subsequent solvothermal method, and MF microspheres were dissolved in the solvent simultaneously. The mixed phase of NaYF4:Yb/Er was transferred into pure α-NaYF4:Yb/Er by calcination. The as-prepared hollow microspheres were well characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectrum (EDS), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), and upconversion (UC) luminescence spectroscopy. It is found that the template can be removed without additional calcination or etching process. α-NaYF4:Yb/Er hollow microspheres exhibit bright upconversion (UC) luminescence under 980 nm laser diode (LD) excitation. Furthermore, the hollow microspheres show sustained and pH-dependent doxorubicin hydrochloride (DOX) release properties; in particular, the emission intensity increases with the release amount of drug, making the release process able to be tracked or monitored by the change of the emission intensity, which demonstrates the high potential of this kind of hollow fluorescent material in drug delivery fields.
Matrix-inducing synthesis and luminescence of microcrystalline red phosphors YVO4:Pb2+,Eu3+ derived from the in situ coprecipitation of hybrid precursors
Su, Xue-Qing,Yan, Bing
, p. 59 - 63 (2006)
Using rare-earth coordination polymers with o-hydroxylbenzoate as a precursor, composing with poly vinyl alcohol as a dispersing medium, a novel red-emitting material of YVO4:xPb2+, yEu3+ (x = 0, 1.0, 1.2, 1.5, 1.8, 2.0, and 5.0 mol %; y = 5 mol %) was synthesized by an in situ coprecipitation process. Its microstructure and micromorphology have been analyzed by x-ray powder diffraction and scanning electronic microscopy, which indicates that there exist some novel cobblestone-like microcrystalline particles. With Pb2+ as a sensitizer, these materials all exhibit strong red emission near 618 nm due to the 5D0 → 7F2 transition of Eu3+ ions. At x = 1.5, YVO4:Pb2+,Eu3+ shows the strongest emission intensity, which indicates an efficient energy transfer from Pb2+ to Eu3+. Pleiades Publishing, Inc., 2006.
Facile hydrothermal synthesis and luminescent properties of Eu-doped CaF2-YF3 alkaline-earth ternary fluoride microspheres
Zhang, Yang,Zhao, Qi,Shao, Baiqi,Lue, Wei,Dong, Xiangting,You, Hongpeng
, p. 35750 - 35756 (2014)
Large-scale CaF2-YF3 alkaline-earth ternary fluoride microspheres with diameters of about 2.5 μm were prepared by a facile hydrothermal method in the presence of disodium ethylenediamine tetraacetate (Na2H2L). The influences of several experimental parameters, such as reaction time, amount of Na2H2L, pH values, and fluoride source on the final products were investigated. The formation mechanism of the as-obtained microspheres was proposed on the basis of all these studies. It is also found that the addition amount of the Y 3+ ions had an effect on the morphology of CaF2-YF 3. The luminescence spectrum of Eu3+-doped CaF 2-YF3 microspheres showed the strong characteristic dominant emission of the Eu3+ ions at 590 nm, indicating that the Eu3+ ions occupy a site of inversion symmetry in the CaF 2-YF3 matrix.
A new sol-gel route to synthesize YPO4:Tb as a green-emitting phosphor for the plasma display panels
Di, Weihua,Wang, Xiaojun,Chen, Baojiu,Zhao, Xiaoxia
, p. 566 - 567 (2005)
This work adopts a novel and low-cost sol-gel route to synthesize Tb 3+-doped YPO4 as a green-emitting phosphor for the plasma display panel (PDP). The phosphor obtained by this route shows improved luminescence efficiency in vacuum ultraviolet (VUV) excitation, compared with that obtained by a solid-state reaction. Copyright
Synthesis of nanocrystalline yttria doped ceria powder by urea-formaldehyde polymer gel auto-combustion process
Biswas,Prabhakaran,Gokhale,Sharma
, p. 609 - 617 (2007)
Nanocrystalline yttria doped ceria powder has been prepared by auto-combustion of a transparent gel formed by heating an aqueous acidic solution containing methylol urea, urea, cerium(III) nitrate and yttrium(III) nitrate. The TGA and DSC studies showed the combustion reaction of the gel initiated at 225 °C and completed within a short period of time. XRD spectrum of the combustion product reveals the formation of phase pure cubic yttria doped ceria during the combustion process. Loose agglomerate of yttria doped ceria particle obtained by the combustion reaction could be easily deagglomerated by planetary ball milling and the powder obtained contains particles in the size range of 0.05-3.3 μm with D50 value of 0.13 μm. The powder particles are aggregate of nanocrystallites with a wide size range of 14-105 nm. Pellets prepared by pressing the yttria doped ceria powder sintered to 95.2% TD at 1400 °C.
Emission Enhancement and Color Tuning for GdVO4:Ln3+ (Ln = Dy, Eu) by Surface Modification at Single Wavelength Excitation
Song, Yan,Shao, Baiqi,Feng, Yang,Lü, Wei,Huo, Jiansheng,Zhao, Shuang,Liu, Man,Liu, Guixia,You, Hongpeng
, p. 282 - 291 (2017)
The surface modification can realize systematically the emission enhancement of GdVO4:Ln3+ (Ln = Dy, Eu) microstructures and multicolor emission at single component. The structure, morphology, composition, and the surface ligands modification of as-prepared samples were studied in detail. It is found that the surface-modified ligands can act as sensitizer to improve the emission of the Eu3+ and Dy3+ ions via the energy transfer besides the VO43--Eu3+/Dy3+ process. More importantly, under a single wavelength excitation, the emission color can be effectively tuned by manipulating the doping ratio of the Eu3+ ions in the internal crystal lattice and the Tb3+ ions in the external surface ligands, simultaneously. And further, multicolor emissions are obtained under single wavelength excitation due to the high overlapping between the VO43- absorption and the π-π? electron transition of the ligands. These findings may open new avenues to design and develop new highly efficient luminescent materials.
Europium-doped NaYF4 nanoparticles cause the necrosis of primary mouse bone marrow stromal cells through lysosome damage
Ge, Kun,Sun, Wentong,Zhang, Shaohan,Wang, Shuxian,Jia, Guang,Zhang, Cuimiao,Zhang, Jinchao
, p. 21725 - 21734 (2016)
Applications of europium-doped NaYF4 (NaYF4:Eu3+) nanoparticles in biomedical fields will inevitably increase their exposure to humans, therefore, the assessment of toxicities must be taken into consideration. It was reported that NaYF4:Eu3+ nanoparticles could accumulate in the bone. However, the potential effect of NaYF4:Eu3+ nanoparticles on bone marrow stromal cells (BMSCs) has not been reported. In this study, NaYF4:Eu3+ particles with diameters of 50 and 200 nm (NY50 and NY200) were prepared and characterized by scanning electron microscopy, transmission electron microscopy, powder X-ray diffraction, photoluminescence excitation and emission spectra, and dynamic light scattering. The cytotoxicity of NaYF4:Eu3+ particles on BMSCs and the associated mechanisms were further studied. The results indicated that NaYF4:Eu3+ particles could be uptaken into BMSCs and primarily localized in the lysosome. NaYF4:Eu3+ particles effectively inhibited the viability of BMSCs in a size-dependent manner at 24 and 48 h. After cells were treated with 20 μg mL-1 of NY50 and NY200 for 24 h, NaYF4:Eu3+ particles could trigger cell necrosis in a size-dependent manner. The percentage of necrotic BMSCs (PI+/Annexin V-) increased to 15.93 and 14.73%. Necrosis was further verified by increased lactate dehydrogenase leakage. Meanwhile, both NY50 and NY200 induced an increased cell population in the S and G2/M phases. The following mechanism is involved in NaYF4:Eu3+ particle-induced BMSCs necrosis: the NaYF4:Eu3+ particles lead to lysosomal rupture by lysosomal swelling, permeabilization of lysosomal membranes, and increased cathepsins B and D. In addition, NaYF4:Eu3+ particle-induced BMSCs necrosis is also directly caused by the overproduction of ROS through injury to the mitochondria. This study provides novel evidence to elucidate the toxicity mechanisms for bone metabolism and may be beneficial to more rational applications of these nanomaterials in the future.
Preparation and characteristics of core-shell structure Y 3Al5O12:Yb3+@SiO2 nanoparticles
Sun, Yan-Hui,Yang, Zhong-Min,Xie, Cheng-Ning,Jiang, Zhong-Hong
, p. 1 - 9 (2012)
The club-shape (Y0.98Yb0.02)3Al 5O12 nanoparticles (YAG:Yb3+), which were synthesized by the co-precipitation method, had been successfully coated with silica from hydrolysis and condensati
Site-Bi3+ and Eu3+ dual emissions in color-tunable Ca2Y8(SiO4)6O2:Bi3+, Eu3+ phosphors prepared via sol-gel synthesis for potentially ratiometric temperature sensing
Li, Kai,Van Deun, Rik
, p. 86 - 95 (2019)
A series of Ca2Y8(SiO4)6O2 (CYSO):Bi3+, Eu3+ phosphors were prepared via a Pechini-type sol-gel reaction method. The refinement results for CYSO:Bi3+, Eu3+ phosphors implied that they had a pure phase. The blue-green emission ascribed to Bi3+ 3P1→1S0 transition was generated upon UV excitation in Bi3+ singly-doped CYSO samples. Spectral analysis indicated that two main emission bands around 414 and 494 nm correspond to two kinds of Bi3+ occupying the crystal lattices of 4f and 6 h available for Y3+ in CYSO, denoted as Bi3+(2) and Bi3+(1), respectively. A broad spectral overlap between Bi3+ emission and Eu3+ excitation spectra implied the existence of energy transfer from Bi3+ to Eu3+ ions in CYSO:Bi3+,Eu3+, which resulted in the tunable emission color from blue-green to red. The energy transfer mechanism from Bi3+ to Eu3+ ions was determined to be a dipole-quadrupole interaction. Moreover, the quite different luminescence thermal quenching behaviors between Bi3+(2) and Eu3+ showed good temperature sensing properties with a temperature range of 298–523 K by analyzing the temperature sensitivity of the fluorescent intensity ratio [Bi3+(2)/Eu3+(612)]. The maximum absolute and relative sensitivities reached as high as 0.07174 K-1 (523 K) and 0.958% K?1 (423 K), which can be compared to the highest values of 0.015 K-1 and 1.1%K?1 in reported optical thermometric materials before, respectively, based on the thermally coupled level (TCLs) of Er3+. Meanwhile, the luminescence thermal quenching mechanism in this system was investigated in detail. Results inspire that a feasible method based on site-Bi3+ and Eu3+ emissions is potential as one of candidate strategies for developing novel ratiometric optical thermometry materials.
Host Differential Sensitization toward Color/Lifetime-Tuned Lanthanide Coordination Polymers for Optical Multiplexing
Liang, Hongbin,Ma, Fengkai,Ma, Li,Ou, Yiyi,Su, Fang,Zheng, Lirong,Zhou, Rongfu,Zhou, Weijie,Zhu, Zece
, p. 23810 - 23816 (2020)
Optical multiplexing based on luminescent materials with tunable color/lifetime has potential applications in information storage and security. However, the available tunable luminescent materials reported so far still suffer from several drawbacks of low efficiency or poor stability, thus restraining their further applications. Herein, we demonstrate a strategy to develop efficient and stable lanthanide coordination polymers (LCPs) with tunable luminescence as a new option for optical multiplexing. Their multicolor emission from green to red and naked-eye-sensitive green emission with tunable lifetime (from ca. 300 to ca. 600 μs) can be controlled by host differential sensitization and energy transfer between lanthanide ions. The quantum efficiencies of developed samples range from around 20 % to 46 % and the luminescence intensity/lifetime appear quite stable in polar solvents up to ten weeks. Furthermore, with the aid of inkjet printing and concepts of luminescence lifetime imaging and time-gated imaging, we illustrate their promising applications of information storage and security in spatial and temporal domains.
Mutual solubility between hexane and tri-n-butyl phosphate solvates of lanthanide(III) and thorium(IV) nitrates at various temperatures
Keskinov,Lishchuk,Pyartman
, p. 1144 - 1146 (2007)
The phase diagrams of binary liquid systems consisting of hexane and a tri-n-butyl phosphate (TBP) solvate of an Ln(III) (Ln = Nd, Gd, Y, Yb, Lu) or Th(IV) nitrate at various temperatures are considered. The diagrams show a field of homogeneous solutions and a two-phase field in which phase I is hexane-rich and phase II is rich in [Ln(NO3)3(TBP)3] or [Th(NO3)4(TBP)2]. The miscibility gap in the binary systems narrows with increasing temperature.
Self-assembled three-dimensional NaY(WO4)2:Ln 3+ architectures: Hydrothermal synthesis, growth mechanism and luminescence properties
Huang, Shaohua,Wang, Dong,Wang, Yan,Wang, Liuzhen,Zhang, Xiao,Yang, Piaoping
, p. 140 - 147 (2012)
Novel three-dimensional (3D) flower-like NaY(WO4) 2:Ln3+ (Ln = Eu, Yb/Er, Yb/Tm and Yb/Ho) microstructures with uniform shape and dimension have been prepared using Y(OH)CO3 nanospheres as sacrificial template through a hydrothermal process and followed by a subsequent heat treatment process. The whole process was carried out in aqueous condition without using any organic solvents, surfactant, or catalyst. The phase, morphology, size, and photoluminescence (PL) properties were well characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and high-resolution transmission electron microscopy (HRTEM), photoluminescence (PL) spectra, and kinetic decays, respectively. The results reveal that the as-prepared precursor of NaY(WO 4)2:Eu3+ exhibits interesting white light emission under UV excitation. After annealing, the as-obtained 3D flower-like NaY(WO4)2:Eu3+ microstructures show exclusively red (Eu3+, 5D0 → 7F 2) luminescence. Furthermore, the up-conversion (UC) luminescent properties and the emission mechanisms of NaY(WO4) 2:Yb3+/Ln3+ (Ln = Er, Tm, Ho) microstructures have been systematically studied, which show respective green (Er3+, 4S3/2, 2H11/2 → 4I15/2), blue (Tm3+, 1G4 → 3H6) and yellow-green (Ho3+, 5S2 → 5I8) luminescence under 980 nm NIR excitation.
Enhancing upconversion luminescence of highly doped lanthanide nanoparticles through phase transition delay
Xu, Dekang,Xie, Feiyan,Yao, Lu,Li, Yongjin,Lin, Hao,Li, Anming,Yang, Shenghong,Zhong, Shengliang,Zhang, Yueli
, (2020)
Doping of rare earth (RE) ions in a low-phonon-energy host matrix is an effective strategy to enhance the upconversion luminescence (UCL) of lanthanide-doped nanoparticles. However, doping of optically inactive RE ions at high concentrations can cause an undesirable phase transition of the host matrix, with concomitant decrease in luminescence. Herein, we present a phase-transition-delay protocol to effectively preserve the pure orthorhombic phase of a KLu2F7:Yb3+,Er3+ system, even at high RE dopant concentrations. The proposed concept can be realized by incorporating a set of optically inactive RE dopants, i.e., Y3+ or Gd3+, with different ionic radii to replace the Lu3+ ions in the host matrix to overcome the energy barrier of the phase transition. The nanoparticles were synthesized in a high-boiling solvent or at a high reaction temperature. We observed maximal UCL of Er3+ at different Y3+ or Gd3+ dopant concentrations; the optimal Y3+ or Gd3+ concentration at which maximal UCL is observed is 10 mol% for samples prepared by a water-based hydrothermal route, while it is 30 mol% for samples prepared by an oleic acid-based hydrothermal route. Further, this optimal concentration could be increased to as much as 50 mol% by adopting a high reaction temperature. The high doping of Y3+ or Gd3+ can efficiently lead to enhanced upconversion performance of the final materials (as much as 32-fold and 9-fold enhancements in the upconversion intensity and quantum yield, respectively, are achieved). The UCL enhancement is caused by the break-down of the symmetry of lanthanide sites in the crystal lattice induced by Y3+ or Gd3+, which enhances the energy transfer probabilities between Yb3+ and Er3+. Our findings highlight a convenient route to simultaneously tune the phase transition of the host and upconversion output, and this strategy can be applied to other upconversion host materials.
The sorption properties of carbon nanotubes modified with tetraphenylmethylenediphosphine dioxide in nitric acid media
Turanov,Karandashev,Evseeva,Kolesnikov,Borisenko
, p. 2223 - 2226 (2008)
The distribution of microamounts of La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y nitrates between aqueous solutions of HNO3 and multiwalled carbon nanotubes noncovalently modified with tetraphenylmethylenediphosphine dioxide (L) wa
Multiple ratiometric nanothermometry operating with Stark thermally and non-thermally-coupled levels in upconverting Y2?xMoO6:xEr3+ nanoparticles
Zheng, Teng,Qiu, Xujun,Zhou, Luhui,Runowski, Marcin,Lis, Stefan,Du, Peng,Luo, Laihui
, (2021/02/09)
Contactless optical nanothermometers of high thermal sensitivity are in great demand in various fields. In this work, we applied a facile sol-gel method to synthesize a series of Y2-xMoO6:xEr3+ upconverting nanoparticles (UCNPs), capable of acting as luminescence nanothermometers. Upon 980 nm laser light irradiation, with increasing Er3+ content, the prepared samples show a color-tunable upconversion emission, from green to yellow. Comparison of the thermometric properties determined by the Stark thermally coupled levels (TCLs) with those determined by the Stark non-thermally coupled levels (non-TCLs) showed that the superior thermal sensitivity (maximal Sr = 2.063%K?1 at 303 K) is achieved for the non-TCLs 4F9/2(1)/4S3/2(1). Moreover, a higher content of Er3+ in UCNPs (Y1.88MoO6:0.12Er3+ UCNPs) has been found to lead to a significant increase of Sr (Sr MAX = 2.460%K?1 at 303 K). Y2-xMoO6:xEr3+ UCNPs are promising materials for contactless nanothermometers of high sensitivity.
Generalized synthesis of NaLn(MoO4)2 nano/microcrystals (Ln = La–Lu and Y): The effects of lanthanide contraction, structure, and down-/up-conversion luminescence
Li, Ji-Guang,Li, Siyuan,Meng, Qinghong,Wang, Xuejiao,Xu, Zhixin,Zhu, Qi
, (2020/03/17)
Systematic synthesis of scheelite-type double molybdate nano-/microcrystals NaLn (MoO4)2 (Ln = La–Lu lanthanides and Y) was successfully carried out via hydrothermal reaction at 180 °C without using any organic additive, and the intrinsic effects of lanthanide contraction on phase preference and crystallite morphology were unambiguously observed. It was shown that the products of larger Ln3+ (Ln = La–Dy) and smaller Ln3+ (Ln = Ho–Lu and Y) elements crystallized as tetragonal NaLn (MoO4)2 and new orthorhombic NaLnMo2O8·2H2O structures, respectively, with the latter being able to dehydrate to tetragonal NaLn (MoO4)2 upon calcination at ~300 °C. Y was found to be a demarcation point for the two structures, and phase preference was shown to be influenced by solution pH and MoO42?/Y3+ molar ratio. With Eu3+ as a downconversion (DC) luminescence probe, the effects of Ln type (Ln = La, Gd, Y and Lu) and crystal structure were manifested. Furthermore, the upconversion (UC) luminescence of Yb3+/Ho3+ and Yb3+/Er3+ pairs in NaLu(MoO4)2 was studied for the first time, and strong red and green UC emissions were observed under the 978 nm laser excitation. Besides, the processes/mechanisms of UC were studied via varying the excitation power and were discussed with Yb3+-MoO42- dimer sensitizer.