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Science China Chemistry 2024年第10期67卷 3328-3338页

作者： Peng-Bo Jin Qian-Cheng Luo Ye-Ye Liu Yan-Zhen Zheng Frontier Institute of Science and Technology State Key Laboratory of Electrical Insulation and Power EquipmentMOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed MatterXi’an Key Laboratory of Electronic Devices and Material Chemistry and School of ChemistryXi’an Jiaotong UniversityXi’an 710054China

Single-molecule magnets(SMMs)are a kind of nanosized magnetic materials that are capable of storing massive bytes of *** coupling the spin centers in a proper manner is a usual approach to promote the working temperature(or blocking temperature)for *** delocalized radicals have been widely employed to accomplish this ***,we show a new manner by using weak but multiple B–H^(δ-)···Dy^(3+)inverse hydrogen bonding(IHB)interactions to control the magnetic couplings in a series of dimeric dysprosiacaborane *** approach leads to a record high T_(B)^(100s)of 10 K among non-radical bridged dimeric SMMs,which is mainly ascribed to strong ferromagnetic coupling(4.38 cm^(-1))and the proper alignment of the magnetic principle axes of the adjacent dysprosium(Ⅲ)*** verifying by theoretical calculations,these results demonstrate that IHB interactions can be used to construct strong axial ferromagnetic coupling and enhancing magnetic blocking temperature for SMMs.

关键词： single-molecule magnets carborane dysprosium ferromagnetic coupling inverse hydrogen bond

Effects of oxidation of DyH_3 in Nd–Fe–B sintered magnets

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Chinese Physics B 2015年第10期24卷 467-470页

作者：严高林方之颢 School of Physics and Technology Wuhan University

The effects of oxidation of Dy H3 with respect to dysprosium addition to Nd-Fe-B sintered magnets are *** sintered with the addition of freshly milled dysprosium hydride, dysprosium hydride exposed to air at room temperature for 15 min and dysprosium hydride exposed to air at 100°C for 3.5 hours are studied from the aspects of magnetic properties, microstructures, and their degradation, respectively. It is found that some oxidized dysprosium is distributed in the Nd-rich phase; hence, the decrease of remanence occurred. The degradation results indicate that preoxidised dysprosium can be a major factor in increasing the corrosion rate. The microstructures and corrosion acceleration test suggested that the oxidation is detrimental to remanence.

关键词： rare earth dysprosium magnetic properties oxidation

Thermal bleaching of optical absorption and photoluminescence spectra of γ-irradiated CaF_2:Dy:Pb:Na single crystals

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Journal of Rare Earths 2010年第4期28卷 493-497页

作者： S.M. Moses Kennedy Department of Physics S.S.N. College of Engineering Rajiv Gandhi Salai Kalavakkam-603 110 Chennai Tamil Nadu India

The variation of the optical absorption (OA) and photoluminescence (PL) spectra with temperature was studied on γ-irradiated CaF2:Dy:Pb:Na single crystals. The OA spectrum showed bands around 2.05, 3.20, 3.82 and 6.20 eV which could be attributed to different sodium associated (SA) colour centres (CCs) such as MNa and RA+ . Heating the crystal indicated the annihilation and formation of different SACCs. The excitation spectrum for the characteristic Dy3+ emission at 2.14 eV immediately after irradiation was...

关键词： calcium fluoride optical absorption photoluminescence colour centres dysprosium lead sodium rare earths

Microstructure and microwave electromagnetic properties of Dy^(3+)-doped W-type hexaferrites

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Rare Metals 2011年第5期30卷 505-509页

作者： WANG Lixi HUANG Xiaogu ZHANG Jing WANG Hongzhou ZHANG Qitu XU Naicen College of Materials Science and Engineering Nanjing University of Technology Nanjing 210009 China Jiangsu Provincial Key Laboratory of New Inorganic Materials and Its Composites Nanjing University of Technology Nanjing 210009 China Nanjing Institute of Geology and Mineral Resources Nanjing 210016 China

Ba 1 x Dy x Co 2 Fe 16 O 27 （x = 0.00, 0.05, 0.10, 0.15, and 0.20） was prepared by the solid-state method. The phase structure was studied using powder X-ray diffraction （XRD）, the electromagnetic properties were measured, and the reflection loss of Dy 3＋ -doped ferrite material was calculated using electromagnetic parameters by the transmission line theory. All XRD patterns showed the single phase of the magnetoplumbite barium ferrite without other intermediate phase when x ≤ 0.15. The values of ε ′ and ε ″ increased slightly with Dy 3＋ ions doping. The values of μ″ and μ′ were improved with Dy 3＋ doping, exhibiting excellent microwave magnetic performance. The reasons have also been discussed using the electromagnetic theory. Dy substitution could increase microwave-absorbing performance and broaden frequency band （reflection loss （RL） -10 dB）, and the absorbing peak shifted to high-frequency position. When x = 0.2, ferrite layer exhibited the most excellent microwave-absorbing performance at a thin matching thickness of 1.5 mm. The peak value of RL was around -15 dB, and the frequency band （RL -10 dB） was about 7 GHz （from 8 to 15 GHz）.

关键词： hexaferrites rare earths microwave electromagnetic properties microstructure dysprosium

Electrical conductivity of molten LiF–DyF3–Dy2O3–Cu2O system for Dy–Cu intermediate alloy production

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International Journal of Minerals,Metallurgy and Materials 2019年第6期26卷 701-709页

作者： Shu-mei Chen Chun-fa Liao Jue-yuan Lin Bo-qing Cai Xu Wang Yun-fen Jiao Institute of Metallurgy and Chemical Engineering Jiangxi University of Science and Technology

Dy–Cu intermediate alloys have shown substantial potential in the field of magnetostrictive and magnetic refrigerant ***,this study focused on investigating the electrical conductivity of molten-salt systems for the preparation of Dy–Cu alloys and on optimizing the corresponding operating *** electrical conductivity of molten LiF–DyF3–Dy2O3–Cu2O systems was measured from 910 to 1030°C using the continuously varying cell constant *** dependencies of the LiF–DyF3–Dy2O3–Cu2O system conductivity on the melt composition and temperature were examined *** optimal operating conditions for Dy–Cu alloy production were determined via analyses of the electrical conductivity and activation energies for conductance,which were calculated using the Arrhenius *** conductivity of the molten system regularly increases with increasing temperature and decreases with increasing concentration of Dy2O3 or Cu2O or *** activation energy Eκof the LiF–DyF3–Dy2O3 and LiF–DyF3–Cu2O molten-salt systems increases with increasing Dy2O3 or Cu2O *** regression functions of conductance as a function of temperature(t)and the addition of Dy2O3(W(Dy2O3))and Cu2O(W(Cu2O))can be expressed asκ=-2.08435+0.0068t-0.18929W(Dy2O3)-0.07918W(Cu2O).The optimal electrolysis conditions for preparing the Dy–Cu alloy in LiF–DyF3–Dy2O3–Cu2O molten salt are determined to be 2.0wt%≤W(Dy2O3)+W(Cu2O)≤3.0wt%and W(Dy2O3):W(Cu2O)=1:2 at 970 to 1000°C.

关键词： electrical conductivity molten salt Dy–Cu alloy dysprosium oxide cuprous oxide

Effect of Dy substitution on the microstructure and magnetic properties of nanograin Nd-Fe-B single-phase alloys

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International Journal of Minerals,Metallurgy and Materials 2010年第3期17卷 335-339页

作者： Zhi-an Chen Ji Luo Zhi-meng Guo School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China

Nanocrystalline single-phase alloys with the nominal compositions （at%） of Nd12.3-xDyxFe79.7Zr0.8Nb0.8Cu0.4B6.0 （x=0, 0.5, 1.5, and 2.5） were prepared by melt-spinning and subsequent annealing. X-ray diffraction analysis shows that the as-spun ribbons were mainly com- posed of the amorphous phase. A slight content of Dy stabilizes the amorphous phase during annealing treatment. The grain size becomes smaller and the coercivity of the annealed ribbon is gradually improved with the increase of Dy content. Excessive Dy is harmful to the remanence. It is found that no intergramtlar phase exists between the grains by high-resolution transmission electron microscopy, and the grain boundaries are crystallographically coherent in the optimally annealed sample. The optimum magnetic properties of remanence （Jr=1.09 T）, coercivity （Hei=1048 kA/m）, and maximum magnetic energy product （（BH）m=169.5 kJ/m3） are obtained from the x=0.5 ribbon in a post heat-treated state （700℃, 10 min）.

关键词： NdFeB magnets dysprosium nanocrystalline amorphous grain size magnetic properties

Magnetron sputtered Dy2O3 with chromium and copper contents for antireflective thin films with enhanced absorption

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Journal of Rare Earths 2019年第9期37卷 989-994,I0004页

作者： Shahid M. Ramay Asif Mahmood Hamid M. Ghaithan Nasser S. Al-Zayed Adnan Aslam Abdullah Murtaza Nisar Ahmad Saadat A. Siddiqi Murtaza Saleem Physics and Astronomy Department College of ScienceKing Saud University RiyadhSaudi Arabia Chemical Engineering Department College of EngineeringKing Saud University RiyadhSaudi Arabia Department of Physics The University of Lahore1-KM Raiwind RoadLahore. Pakistan Interdisciplinary Research Centre in Biomedical Materials COMSATS Institute of Information TechnologyDefence RoadOff Raiwind RoadLahore Pukiston Department of Physics SBASSELahore University of Management Sciences (LUMS)Lahore 4792Pakisran

Dy2O3 is a rare earth oxide having a number of advanced applications in various fields including protective or antireflective coatings,Main objective of this novel research work is to check the effect of Cr and Cu addition on different properties of Dy2O3 and achievement of antireflective thin films with enhanced abso *** films of these materials we re deposited using DC magnetron with reactive *** studies reveals the crystalline nature of thin films having Dy2O3(222)reflection in all samples with Cr2O3(116)and CuO(111)reflections in Cr and Cu containing *** emission scanning electron microscopy demonstrates the homogeneous deposition of thin films with uniform shape,size and distribution of *** index,extinction coefficient and absorption coefficient significantly increase while optical reflectance decreases with Cr and Cu mediation corroborating an improved antireflective *** imaginary part of dielectric constant is found to increase slightly with low tangent loss for Cr containing composition co nsidered favorable for energy storage applications.

关键词： Thin films dysprosium oxide X-ray diffraction FESEM Optical properties Anti-reflective

Indirect neutron radiography experiment on dummy nuclear fuel rods for pressurized water reactors at CMRR

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Nuclear Science and Techniques 2024年第11期35卷 13-27页

作者： Yong Sun Qi-Biao Wang Peng-Cheng Li Ming Xia Bin Liu He-Yong Huo Wei Yin Yang Wu Sheng Wang Chao Cao Xin Yang Run-Dong Li Hang Li Bin Tang Institute of Nuclear Physics and Chemistry China Academy of Engineering PhysicsMianyang 621000China School of Physics and Electronic Engineering Sichan University of Science and EngineeringZigong 643000China

Nuclear energy is a vital source of clean energy that will continue to play an essential role in global energy production for future *** fuel rods are core components of nuclear power plants,and their safe utilization is *** to its inherent high radioactivity,indirect neutron radiography(INR)is currently the only viable technology for irradiated nuclear fuel rods in the field of energy *** study explores the experimental technique of indirect neutron computed tomography(INCT)for radioactive *** project includes the development of indium and dysprosium conversion screens of different thicknesses and conducts resolution tests to assess their ***,pressurized water reactor(PWR)dummy nuclear fuel rods have been fabricated by self-developing substitute materials for cores and outsourcing of mechanical *** research on the INR is performed using the developed dummy nuclear fuel *** sparse reconstruction technique is used to reconstruct the INR results of 120 pairs of dummy nuclear fuel rods at different angles,achieving a resolution of 0.8 mm for defect detection using INCT.

关键词： Conversion screen dysprosium Indirect neutron computed tomography Dummy nuclear fuel rods

Photo-luminescence properties and thermo-luminescence curve analysis of a new white long-lasting phosphor: Ca_2MgSi_2O_7:Dy^(3+)

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Journal of Rare Earths 2009年第5期27卷 749-752页

作者：林林赵仲华张慰萍郑志强尹民 Department of Physics Fujian Normal University Department of Physics University of Science and Technology of China Department of Physics the City College of the City University of New York

A white long-lasting phosphor Ca2MgSi2O7:Dy3+ was prepared by the solid-state reaction. A strong band peaked at 260 nm was shown in the excitation spectrum of 578 nm emission, which might be attributed to the oxygen deficiency of the host. After irradiated with 254 nm for 4 min, the white afterglow of the sample could be seen for 3 h. Moreover, the depths and frequency factors of trap centers were calculated from the thermo-luminescence curve of the sample, which indicated that the trap centers corresponding to the 414 K band were more helpful to the long-lasting phosphorescence.

关键词： white long-lasting phosphor silicate dysprosium thermo-luminescence rare earths

Oxide evolution in NdDy-Fe-B magnet during aging process

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Journal of Rare Earths 2012年第10期30卷 1020-1023页

作者：王景代冯海波李安华李岩峰朱明刚李卫 Division of Functional Materials Central Iron and Steel Research Institute

Sintered NdDy-Fe-B magnets were made from strip cast flakes by powder metallurgy method. For the magnet with 6 wt.% Dy substituted Nd, a remarkable coercivity increase of 70% was obtained after aging at 900 ℃ for 2 h and a high coercivity of 23.5 kOe was achieved after aging at 520 ℃ for 2 h. The average diameter of the oxide particles decreased during the following 900℃ aging treatment. Dy and O diffusion from oxide particles to Nd-rich phase during the aging process was observed. The oxide evolution and Dy element diffusion were helpful to the coercivity enhancement.

关键词： permanent magnet aging dysprosium oxide coercivity rare earths