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Tuning Magnetic Relaxation in Square-Pyramidal Dysprosium Single-Molecule Magnets Using Apical Alkoxide Ligands

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CCS Chemistry 2021年第12期3卷 388-398页

作者： Zhenhua Zhu Yi-Quan Zhang Xiao-Lei Li Mei Guo Jingjing Lu Shuting Liu Richard A.Layfield Jinkui Tang State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022 University of Chinese Academy of Sciences Beijing 100049 Jiangsu Key Lab for NSLSCS School of Physical Science and TechnologyNanjing Normal UniversityNanjing 210023 University of Science and Technology of China Hefei 230026 Department of Chemistry School of Life SciencesUniversity of SussexBrighton BN19QR

Eight square-pyramidal Dysprosium complexes of the type[Dy(X)(DBP)_(2){TMG(H)}_(2)]were synthesized,where TMG(H)denotes 1,1,3,3-tetramethylguanidine,X denotes an alkoxide ligand or anionic guanidinate in the apical position,and DBP denotes 2,6-di-tert-butylphenoxide.These complexes,expressed as 5-Dy-X,are single-molecule magnets(SMMs)with properties dependent on the nature of the apical X ligand.

关键词： single-molecule magnets Dysprosium magnetic relaxation energy barrier twocoordination design

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 challenging.Herein, 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

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

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

Photoluminescence and thermoluminescence properties of Dysprosium doped zinc metaborate phosphors

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Journal of Rare Earths 2008年第2期26卷 203-206页

作者：李娟张纯祥唐强郝景权张彦立苏锵王淑彬 Chemistry and Biology College Beihua University Department of Physics Sun Yat-Sen University Key Laboratory of Rare Earth Chemistry and Physics Changchun Institute of Applied Chemistry Chinese Academy of Sciences Ionizing Radia- tion Division National Institute of Metrology

Polycrystalline powder samples of Dysprosium doped Zn（BO2）2 phosphors were prepared by solid state reaction in air at high temperature and characterized by X-ray powder diffraction. The IR, Photoluminescence （PL）, diffuse reflectance and three-dimensional （3D） thermoluminescence （TL） emission spectrum after 60^Co gamma ray irradiation were investigated. The characteristic 3D TL emission bands at about 425, 481 and 573 um with a main emission band of around 573 um were attributed to the host emission, 4^F9/2→6H15/2 and F9/2→6^H13/2 f-f transitions of Dy^3＋ ions. No emission from Dy^2＋ ions was observed in the measurement wavelength range. The TL-dose response of the Zn（BO2）2：Dy polycrystalline powder sample to gamma ray radiation in the range from 1 to 100 Gy at clinical dose levels was almost linear. The experimental results showed that Zn（BO2）2：Dy had potential use as the materials of gamma-ray thermoluminescence dosimeter （TLD） for clinical dosimetry.

关键词： thermoluminescence Dysprosium dosimetry zinc metaborate Gamma-ray rare earths

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 desired.In 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 diluent.The obtained data were analyzed using the chemically based model in order to correlate the equilibrium distribution ratios.In 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 equation.As 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 3.5.In 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

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 ball-milling.The effect of ball-milling time on the structure and magnetic properties of the powders was studied.The 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 powders.Further TEM observation shows that the grains are fine and uniform.The 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 process.Moreover,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 ally.As 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

The Electroreduction of Gadolinium and Dysprosium Ions in Equimolar NaCl-KCl Melt

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American Journal of Analytical Chemistry 2013年第6期4卷 39-46页

作者： Hasbi B. Kushkhov Aziza S. Uzdenova Mahmoud M. A. Saleh Abdalkader M. F. Qahtan Lily A. Uzdenova Kabardino-Balkarian State University Nalchik Russia

The mechanism of rare earth metals (Gd and Dy) chloride complexes electroreduction on the tungsten electrode in equimolar NaCl-KCl melt at 973 K has been studied by linear and cyclic voltammetry. Some kinetic parameters of processes were calculated. It was shown that the tungsten electrode was indifferent to gadolinium and Dysprosium which were reduced on the surface. We found that the discharge mechanism of gadolinium and Dysprosium chloride complexes was described by three-electron step when the steady-state conditions of polarization were limited by the mass transfer stage. The conditions of nonstationary polarization made the slowness of the charge transfer stage. The diffusion coefficient of gadolinium and Dysprosium ions was calculated, the diffusion coefficient of GdCl3-6 ions was (0.9 ± 0.2) × 10-5 cm2.s-1, and for DYCI3-6 ions, it was (1.60 ± 0.2) × 10-5 сm2.s-1.

关键词： Molten Chlorides Gadolinium Trichloride Dysprosium Trichloride The Electroreduction Mechanism Tungsten Electrode Linear and Cyclic Voltammetry The Diffusion Coefficient

The First mixed(phthalocyaninato)(corrolato) Dysprosium Triple-decker complex

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The First mixed(phthalocyaninato)(corrolato) dysprosium Trip...