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Luminescent properties of dysprosium(III) ions in LaAlO_3 nanocrystallites

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Journal of Rare Earths 2011年第12期29卷 1195-1197页

作者： K.Lemański P.J.Dereń Institute of Low Temperature and Structure Research Polish Academy of Sciences

The absorption and emission spectra as well as decay time profile of Dy^3＋ ions in LaAlO3 nanocrystals were analyzed. The crystal structure of LaAlO3 was confirmed from XRD measurement. The emission peaks from blue to red came from main emitting level of dysprosium ^4F9/2 to the ground and other excited levels of Dy^3＋ ions. Cross relaxation process led to non-radiative quenching of luminescence, so that the lifetime of the ^4F9/2 energy level ions decreased with increasing amount of doped Dy^3＋ ions. The cross relaxation transfer rates were experimentally determined as a fimction of Dy^3＋ concentration.

关键词： LaAlO3 dysprosium luminescence nanocrystals cross relaxation rare earths

dysprosium Modification of Cobalt Ferrite Ionic Magnetic Fluids

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Journal of China University of Mining and Technology 2005年第4期15卷 354-356页

作者： JIANG Rong-li LIU Yong-chao GENG Quan-rong ZHAO Wen-tao School of Chemical Engineering and Technology China University of Mining ＆ Technology Xuzhou Jiangsu 221008 China

dysprosium composite cobalt ferrite ionic magnetic fluids were prepared by precipitation in the presence of Tri-sodium citrate. Influence of dysprosium modification on magnetic property is studied. The result shows that magnetic response toward exterior magnetic field can be improved by adding Dy3+. Studies also show that the increase of reaction temperature may improve the modification effect of dysprosium. By adding dysprosium ions, the average diameter of the magnetic nanoparticles will be decreased evidently. It is clear that the particles appear as balls. Cobalt ferrite with sizes of 12-15 nm, rare earth composite cobalt ferrite with sizes of 6-8 nm.

关键词： cobalt ferrite magnetic fluids dysprosium modification mechanism magnetic property

Structure and magnetic properties of nanocrystalline dysprosium powders

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Rare Metals 2020年第1期39卷 28-35页

作者： Hong-Jian Li Qiong Wu Ming Yue Yu-Qing Li Rong-Chun Zhu Jing-Ming Liang Jiu-Xing Zhang College of Materials Science and Engineering Key Laboratory of Advanced Functional MaterialsMinistry of Education of ChinaBeijing University of TechnologyBeijing100124China

In this current study,nanocrystalline Dy powders were prepared by melt-spinning and subsequent highenergy *** effect of ball-milling time on the structure and magnetic properties of the powders was *** crystal structure and microstructure of the melt-spun ribbons and ball-milled powders were observed by X-ray diffraction(XRD),scanning electron microscopy(SEM)and transmission electron microscopy(TEM).Magnetic measurement of all samples was performed with vibrating sample magnetometer(VSM).XRD results indicate that the average crystal grain size of the powders decreases from 90.09 nm of the ribbons to 10.42 nm of the4-h ball-milled *** TEM observation shows that the grains are fine and *** Neel temperature(TN)decreases from 182 K of the ribbons to 172 K of the powders,while the Curie temperature(TC)increases from100 to 130 K,demonstrating that the grain size has substantial influence on the magnetic transition ***,at 60 K,as the ball-milling time increases,the coercivity of the powders increases first,peaking at 0.48 T for 2-h milling,then drops again,while the remanence of the powders decreases monotonic *** a result,the powders milled for 2 h exhibit an optimal maximum energy product of 64.0 kJ·m-3,demonstrating the good potential of these powders as a permanent magnet at low temperatures.

关键词： dysprosium Nanocrystalline Low temperature Magnetic properties

Solvent extraction equilibrium of dysprosium(Ⅲ) from nitric acid solutions with 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester

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Transactions of Nonferrous Metals Society of China 2010年第4期20卷 707-711页

作者： HUANG Ying TANAKA Mikiya Research Institute for Environmental Management Technology National Institute of Advanced Industrial Science and Technology （AIST） 16-10nogawa Tsukuba Ibaraki 305-8569 Japan School of Energy and Environment Southeast University Nanjing 210096 China

In view of the importance of solvent extraction of rare earth metals with the acidic organophosphorous reagent,the development of a chemically based model applicable to high concentration is *** the present study,the equilibrium distribution of dysprosium(Ⅲ)between an aqueous nitric acid solution and 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (PC88A)was measured in the range of an initial aqueous dysprosium(Ⅲ)concentration from 1.0×10-3to 1.0×10-1kmol/m 3and PC88A concentration from 0.16 to 0.65 kmol/m3in Shellsol D70 as the *** obtained data were analyzed using the chemically based model in order to correlate the equilibrium distribution *** this model,dysprosium(Ⅲ)was assumed to be extracted with the PC88A dimer as a 1:3 complex,the activities were considered for the aqueous species,and the effective concentration of the PC88A dimer was calculated using Alstad's empirical *** a result,the apparent extraction equilibrium constant was determined to be 253(kmol·m- 3)-2with an excellent correlation between the experiment and calculation results in the wide range of the logarithm of the distribution ratio from-2 to *** conclusion,the methodology in this model would be effective for quantitative description of solvent extraction behavior of general rare earth elements as well as dysprosium.

关键词： solvent extraction dysprosium 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester(PC88A) nitric acid equilibrium

Comparison of thermoluminescence spectra of MgB_4O_7 doped with dysprosium and manganese

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Journal of Rare Earths 2013年第11期31卷 1039-1042页

作者：谭志坚兰婷婷高丽张纯祥刘小伟罗达玲唐强 School of Physics Science and Engineering Sun Yat-sen University School of Sciences South China University of Technology

A series of magnesium borate phosphors MgB4O7：Dy, MgB4O7：Mn and MgB4O7：Dy,Mn were prepared and their ther-moluminescence （TL） emission spectra were measured. TL emission bands in 480, 575 and 660 nm at 200 and 360 oC were observed in the MgB4O7：Dy due to the transitions of the trivalent rare earth ions Dy3＋. The glow peaks of broad wavelength band around^580 nm at 180 and^290 oC were observed in MgB4O7：Mn due to the emission of Mn2＋ions. The main glow peak of MgB4O7 co-doped with Dy and Mn appeared in 580 nm at^360 oC. When MgB4O7 was co-doped with Dy （0.5 mol.%） and different concentrations of Mn （0.01 mol.%-1.0 mol.%）, the peak in 580 nm at 360 °C was intensified and broadened as the concentration of Mn increased, while the peaks in 480, 680 and 750 nm below 300 °C remained the characteristic emission of Dy3＋and were reduced in intensity. The emission spectra of the MgB4O7：Dy,Mn phosphor showed that the competitive de-excitation processes between Dy3＋and Mn2＋existed and the energy transfer occurred from Dy3＋to Mn2＋. These results meant that rare earth and Mn ions in MgB4O7：Dy,Mn might cause the formation of defects complex that dominated the traps and recombination.

关键词： magnesium borate therrnoluminescence dysprosium manganese rare earths

Luminescence properties of dysprosium doped YVO_4 phosphor

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Journal of Rare Earths 2018年第12期36卷 1245-1249页

作者： H.J.Rajendra C.PANDurangappa D.L.Monika Department of Physics RNS Institute of TechnologyChannasandra Department of Physics SJB Institute of Technology

Trivalent dysprosium(Dy) activated nanocrystalline yttrium vanadate(YVO) phosphor was synthesized via co-precipitation method. The prepared samples were characterized by X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR), scanning electron microscopy(SEM), optical absorption and photo luminescence(PL) techniques. The XRD patterns reveal the tetragonal crystalline phase. SEM images reveal that Dy doped YVOnanocrystals are agglomerated. EDAX confirms the formation of YVO:Dy. FTIR spectrum shows two strong absorption bands at 459 and 761 cm. Optical absorption spectrum showed the surface defects in the as-prepared samples. The PL emission spectrum shows two characteristic emission bands at 485 and 575 nm. The strong yellow emission peak at 575 nm is assigned to ~4 F→~6 Hhyper sensitive transition of Dyions, Study of CIE chromaticity diagram indicates the suitability of the phosphor for the development of yellow-green LEDs.

关键词： Precipitation Yttrium vanadate dysprosium X-ray diffraction Photoluminescence Rare earths

Synthesis and Crystal Structure of Tri-(2-mercaptopyridine N-oxide)bis(dimethyl sulfoxide) dysprosium(III)

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Chinese Journal of Structural Chemistry 2002年第5期21卷 520-524页

作者：牛德仲陈久桐等 DepartmentofChemistry XuzhouNormalUniversityXuzhou221009China FujianInstituteofResearchontheStructureofMatter TheChineseAcademyofSciencesFuzhou350002China

A range of rare earth metal complexes of 2-mercaptopyridine N-oxide (Hmpo) have been synthesized, and studied by elemental analysis and IR spectroscopic technique. Crystal structure of Dy(mpo)3(DMSO)2 (DMSO = dimethyl sulfoxide) has been determined. The complex crystallizes in the triclinic system, space group P with lattice parameters: a = 9.602(3), b = 9.803(3), c = 15.498(5) ? a = 89.51(1), b = 85.73(1), g = 62.99(1)? Dc = 1.787 g/cm3, C19H24N3O5S5Dy, Mr = 697.21, Z = 2, F(000) = 690, = 3.321mm-1, the final R = 0.0237 and wR = 0.0587 for 4116 reflections with I > 2s(I). The coordination number of dysprosium (Ⅲ) is eight, and its coordination geometry is a somewhat distorted square antiprism with O(3), O(4), O(5), S(3) and O(1), O(2), S(1), S(2) at the tetragonal bases (dihedral angle between their mean planes is 2.9(1)). Around the Dy atom, three five-membered ring planes (Dy, O, N, C, S) make the dihedral angles of 74.42, 11.31 and 83.72, respectively.

关键词： dysprosium gadolinium neodymium 2-mercaptopyridine N-oxide

Hydrangea flower-like nanostructure of dysprosium-doped Fe-MOF for highly efficient oxygen evolution reaction

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Rare Metals 2022年第3期41卷 844-850页

作者： Yan Ma Guo-Mei Mu Yu-Jie Miao Dun-Min Lin Cheng-Gang Xu Feng-Yu Xie Wen Zeng College of Chemistry and Materials Science Sichuan Normal UniversityChengdu 610068China College of Materials Science and Engineering Chongqing UniversityChongqing 401331China

Developing catalysts with high intrinsic activity toward oxygen evolution reaction (OER) has paramount importance to meet the ever-increasing quest for sustainability demands for green energy solutions but ***, a one-step synthesized hydrangea flower-like metal-organic framework (MOF) by dysprosium (Dy)-doped Fe-MOF is reported (Dy_(0.05)Fe-MOF/NF).

关键词： dysprosium reaction intrinsic

Synthesis and Structure of Tetrahydrofuran Adduct of Tris(indenyl)dysprosium

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Chinese Journal of Structural Chemistry 1999年第5期18卷 373-377页

作者：周锡庚黄小荥等 DepartmentofChemistry FudanUniversityShanghai2004 DepartmentofChemistry FudanUn

Reaction of DyCl 3 with excessive amount of K and indene in THF forms (C 9H 7) 3Dy(THF), which crystallizes in hexagonal system, space group P6 3 with a= b=11.719(5), c=10.167(2) , V=1211(1)  3, M r=580.07, D c =1 590 g/cm 3, Z=2, F(000)=578, μ =31.31 cm -1 . Final R =0.043 and R w =0.055 for 1273 observed reflections with I>3σ(I ). The crystal structure shows that in the title compound the indenyl group is bonded to dysprosium in an η 3+η 2 fashion, and is bent over the C(1) and C(3) axis by 12.7°. Its nodal carbon atoms C(4) and C(9) which are weakly bonded to the metal atom are at distances of 2.92(1) and 2.94(1) , respectively. The average Dy-C( η 3) bond distance is 2.66(1) .

关键词： dysprosium indenyl organolanthanide crystal structure