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Rigid Dysprosium(Ⅲ)Single-Molecule Magnets Exhibit Preserved superparamagnetism in Solution

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Chinese Journal of Chemistry 2022年第5期40卷 563-570页

作者： Xiali Ding Qiancheng Luo Yuanqi Zhai Xufeng Zhang Yi Lv Xinliang Zhang Chao Ke Chao Wu Yanzhen Zheng Frontier Institute of Science and Technology(FIST) State Key Laboratory of Mechanical Behavior for MaterialsMOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed MatterXi'an Key Laboratory of Sustainable Energy and Materials ChemistrySchool of Chemistry and School of PhysicsXi'an Jiaotong University99 Yanxiang RoadXi'anShaanxi710054 China Department of Hepatobiliary Surgery and The First Affiliated Hospital of Xi'an Jiaotong University 277 West Yanta RoadXi'anShaanxi710061 China Department of Spine Surgery Honghui HospitalXi'an Jiaotong University76 Nanguo RoadXi'anShaanxi710054 China Department of Orthopaedics and Trauma Hong Hui HospitalCollege of MedicineXi'an Jiaotong University555 East Youyi RoadXi'anShaanxi710054 China

Molecules with long preserved magnetic moments are perceived as the smallest units for storing bytes,which could bring a new revolution for information ***,the rational design of such molecules remains *** two rigid adamantanol ligand based dysprosium(III)complexes([Dy(1-AdO)_(2)(py)_(5)]BPh_(4)-1 and[Dy(2-AdO)_(2)(py)_(5)]BPh_(4)-2)with pentagonal-bipyramidal coordination geometry and local D5h symmetry were successfully prepared,which display excellent single-molecule magnet(SMM)behavior(U_(eff)≈1835 K,T_(B)_(ZFC)≈24 K,T_(B)^(100s)≈17 K and T_(B)^(H)=23 K for 1;U_(eff)≈1756 K,T_(B)^(ZFC)≈20 K,T_(B)^(100s)≈16 K and T_(B)^(H)=23 K for 2)due to the much weakened vibration in low energy ***,the large energy barriers and high blocking temperatures for these two complexes in solid states are well preserved in *** is never observed in previous studies of SMMs,indicating that the adamantanol is rigid and can be introduced to make the composed molecules stable enough to maintain the solid state magnetic property in solution.

关键词： Molecularmagnets Lanthanide D_(sh)-symmetry superparamagnetism Solution

Unique structural and magnetic traits of Nd3+-substituted Co-Zn nanoferrites

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Journal of Rare Earths 2019年第10期37卷 1108-1115页

作者： M.A.Almessiere Department of Physics College of Science Imam Abdulrahman Bin Faisal University Department of Nano-Medicine Research Institute for Research & Medical Consultations (IRMC) Imam Abdulrahman Bin Faisal University

Because of the technological potential of magnetic spinel nanoferrites, we prepared neodymium ion(Nd3+)-substituted cobalt-zinc ferrites(CZFs) with the form Co0.5 Zn0.5 NdxFe2 exO4(0.03≤x≤0.05) via a hydrothermal method. The as-prepared samples were thoroughly characterized using various analytical techniques. XRD, FTIR and FESEM analyses confirm the formation of a cubic spinel phase of the CZFNPs(CZF nanoparticles). A decrease in the lattice parameter due to the substitution of Fe3+by Nd3+in the lattice structures is manifested in the XRD refinement data. The magnetic properties of the proposed CZFNPs were evaluated in terms of the saturation magnetization, remanence, coercivity, squareness ratio and magnetic moment. These CZFNPs exhibit superparamagnetic behaviors at room ***, the Nd3+inclusion does not significantly affect the measured magnetizations and coercivities of the CZFNPs. Samples containing 0.01 and 0.03 Nd3+exhibit lower saturation magnetizations than that of the pristine product. The squareness ratios much less than 0.53 are ascribed to surface spin disordering. The unique magnetic traits of the synthesized CZFNPs are primarily attributed to the substitution of Fe3+ions, with smaller ionic radii, by Nd3+ions, with larger ionic radii. The proposed CZFNPs may be useful for diverse magneto-optic applications.

关键词： Spinel nanoferrites Neodymium Magnetic properties Optical properties superparamagnetism Rare earths

Wüstite-type Fe0.78Mn0.22O nanocubes:A new class for high-sensitive T2-weighted magnetic resonance imaging agent

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Journal of Materials Science & Technology 2019年第11期35卷 2485-2493页

作者： Huawei Rong Haihua Hu Jian Zhang Jianjun Wang Mu Zhang Gaowu Qin Yanhui Zhang Xuefeng Zhang Key Laboratory for Anisotropy and Texture of Materials(MOE) School of Materials Science and EngineeringNortheastern UniversityShenyang110819China Shenyang Northeastern Institute of Metal Materials Co. LtdShenyang110108China Institute of Advanced Magnetic Materials Hangzhou Dianzi UniversityHangzhou310012China

Wüstite-type Fe(0.78)Mn(0.22)O nanocubes,with a uniform size of^10 nm in edge length,have been synthesized by thermal-decomposition *** nanocubes exhibited superparamagnetic properties at room temperature,associated with a magnetization of 12.6 emu/*** Fe(0.78)Mn(0.22)O nanocubes present transversal(r2)and longitudinal(r1)relaxivities of 325.9 and 0.518 mM^-1 s^-1 at 7 T for water *** ratio of the r2/r1(629.2)ranks them being the highest sensitivity(r2/r1)comparable to currently reported T2-weighted magnetic resonance imaging(MRI)***,the Fe(0.78)Mn(0.22)O nanocubes were functionalized and demonstrated to be biocompatible when attached to the surface of mesenchymal stem cells,therefore showing the promise as a new class of MRI agents in clinic applications.

关键词： Magnetic resonance imaging(MRI) superparamagnetism FeMn oxides Nanocubes

Synthesis and Characterization of SiO_2 Coated γ-Fe_2O_3 Nanocomposite Powder for Hyperthermic Application

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Journal of Materials Science & Technology 2010年第4期26卷 333-336页

作者： Ji-Hun Yu Jai-Sung Lee Yong-Ho Choa Heinrich Hofmann Korea Institute of Materials Science Changwon 641-831 Korea Division of Materials and Chemical Engineering Hanyang University Ansan 426-791 Korea Swiss Federal Institute of Technology at Lausanne Lausanne CH-1015 Switzerland

SiO2 coated γ-Fe2O3 nanocomposite powder has been successfully synthesized by chemical vapor condensation process and its feasibility on hyperthermic application was investigated in this study. The power loss of SiO2 coated γ-Fe2O3 nanocomposite powder which means the magnetic heating effect under alternative magnetic field was much higher than the single phase γ-Fe2O3 nano powder due to the very fine size under 20 nm and well dispersion in biologically compatible SiO2 matrix. The superparamagnetism and hyperthermic property of SiO2 coated γ-Fe2O3 nanocomposite powder were discussed in terms of microstructural development in this study.

关键词： Hyperthermia Nano-Bio Chemical vapor condensation Silica coated iron oxide nanoparticle superparamagnetism

Detection of Fe 3d electronic states in the valence band and magnetic properties of Fe-doped ZnO film

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Chinese Physics B 2013年第2期22卷 352-356页

作者：陈铁锌曹亮张旺韩玉岩郑志远徐法强奎热西钱海杰王嘉鸥 National Synchrotron Radiation Laboratory University of Science and Technology of China Beijing Synchrotron Radiation Facility Institute of High Energy PhysicsChinese Academy of Sciences

Fe-doped ZnO film has been grown by laser molecular beam epitaxy（L-MBE） and structurally characterized by X-ray diffraction（XRD） and scanning electron microscopy（SEM）,all of which reveal the high quality of the *** secondary phase was *** photoemission spectroscopy（RPES） with photon energies around the Fe 2p-3d absorption edge is performed to detect the electronic structure in the valence band.A strong resonant effect at a photon energy of 710 eV is ***3＋ is the only valence state of Fe ions in the film and the Fe 3d electronic states are concentrated at binding energies of about 3.8 eV and 7 eV～8 *** are no electronic states related to Fe near the Fermi *** measurements reveal a typical superparamagnetic property at room *** absence of electronic states related to Fe near the Fermi level and the high quality of the film,with few defects,provide little support to ferromagnetism.

关键词： Fe-doped ZnO laser molecular beam epitaxy resonant photoemission spectroscopy superparamagnetism

Preparation and properties of a nano TiO_2/Fe_3O_4 composite superparamagnetic photocatalyst

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Rare Metals 2009年第5期28卷 423-427页

作者： LI Yuxiang ZHANG Mei GUO Min WANG Xidong School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Beijing 100083 China College of Engineering Peking University Beijing 100871 China

Nano TiO2/Fe3O4 composite particles with different molar ratios of TiO2 to Fe3O4 were prepared via sol-gel method. X-ray diffraction, transmission electron microscopy, and vibration sample magnetometry were used to characterize the TiO2/Fe3O4 particles. The photocatalytic activity of the particles was tested by degrading methyl blue solution under UV illumination （254 nm）. The results indicate that with the content of TiO2 increasing, the photocatalytic activity of the composite particles enhances, while the magnetism of the particles decreases. When the molar ratio of TiO2 to Fe3O4 is about 8, both the photocatalytic activity and magnetism of the TiO2/Fe3O4 particles are relatively high, and their photocatalytic activity remains well after repeated use.

关键词： photocatalysis superparamagnetism sol-gel method TiO2 Fe3O4

Preparation and Characterization of Hydroxyapatite/γ-Fe_2O_3 Hybrid Nanostructure

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Journal of Wuhan University of Technology(Materials Science) 2013年第2期28卷 215-219页

作者：孙瑞雪陈克正 XU Lei College of Materials Science and Engineering Qingdao University of Science and Technology

The hybrid particles composed of hydroxyapatite （HAp） and ferrite （ γ-Fe203） were synthesized by two-step precipitation method. The effect of reaction temperature on the morphology of the hybrids was also studied. The resultant hybrids were characterized by transmission electron microscopy （TEM） and X-ray diffraction analysis（XRD）. It was found that γ-Fe203 nanoparticles dispersed within the HAp matrix and these hybrids had a feather-like or spherical morphology when synthesized at 90 ℃ or room temperature, respectively. The magnetic properties of the hybrid showed good superparamagnetic feature, and they could be controlled by the external magnetic field.

关键词： hydroxyapatite γ-Fe203 hybrid nanostructure superparamagnetism

Preparation and Properties of Magnetic-fluorescent Microporous Polymer Microspheres

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Chemical Research in Chinese Universities 2018年第4期34卷 684-690页

作者： ZOU Xiaohu WEI Zhizhi DU Jing WANG Xiaotao ZHANG Gaowen Hubei Provincial Key Laboratory of Green Materials for Light Industry School of Materials and ChemicaI Engineering Hubei University of Technology Wuhan 430068 P. R. China

Microporous microspheres can be used as functional nanomaterial carriers for their microporous structure and higher specific surface area. In this study, magnetic fluorescent polymer microspheres were prepared by incorporating Fe304 nanoparticles and CdSe/ZnS quantum dots（QDs） into hyper-crosslinked microporous polymer micro- spheres（HCMPs） via the in situ coprecipitation method and swelling-diffusion. The HCMPs predominantly have mi- cropores, and their specific surface area is as high as 703.4 m2/g. The magnetic-fluorescent microspheres maintain the superparamagnetic behavior of Fe304, and the saturation magnetization reaches 38.6 A.m2/kg. Moreover, the composite microspheres exhibit an intense emission peak at 530 nm and achieve good fluorescence.

关键词： Microporous polymer Magnetic-fluorescent polymer microsphere Hyper-crosslinking superparamagnetism Quantum dot

Controlled Preparation of Monodisperse CoFe_2O_4 Nanoparticles by a Facile Method

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Journal of Wuhan University of Technology(Materials Science) 2011年第2期26卷 258-262页

作者：王海 Key Laboratory of Fiber Optic Sensing Technology and Information Processing of Ministry of Education Wuhan University of Technology

CoFe2O4 nanoparticles （NPs） were synthesized by coprecipitation method using FeCl3·6H2O and CoCl2·6H2O as *** synthesized conditions were optimized,such as added means of precipitator,quantity of precipitator,the mol ratio of Fe 3＋ to Co2＋,reaction temperature and pH *** synthesized material was characterized by XRD,TEM,FTIR,EDS,Raman and its magnetic properties were studied by *** experimental results confirm that the sample is cubic spinel structure CoFe2O4 with a narrow size distribution and a good dispersion ***2O4 NPs with well-controlled shape and size was obtained at 70℃.The magnetic properties indicate superparamagnetic behavior and good saturated magnetization.

关键词： CoFe2O4 nanoparticles coprecipitation method monodispersity superparamagnetism