Well-defined Fe3O4/Mn OOH nanoparticles with 61.1 emu·g-1in magnetization intensity and 90.53 m2·g-1in surface area have been synthesized by a new-style of high-frequency impinging stream(HFIS)reactor.In thi...Well-defined Fe3O4/Mn OOH nanoparticles with 61.1 emu·g-1in magnetization intensity and 90.53 m2·g-1in surface area have been synthesized by a new-style of high-frequency impinging stream(HFIS)reactor.In this reactor,two streams first collided together to form nano Fe3O4suspension,which subsequently flew through an S-shaped main channel to generate high-frequency reversing high-gravity fields.At the same time,24 thin liquid sheets impinged into the main channel at the frequencies higher than 100 Hz to create nano Fe3O4/Mn OOH colloids.The obtained powders were characterized by transmission electron microscopy/energy dispersive spectrometer(TEM/EDS),X-ray diffraction(XRD),Brunner–Emmet–Teller(BET)and vibrating sample magnetometer(VSM).Experimental results indicated that low coating ratio prolonged the induction period of heterogeneous nucleation.The high-frequency impingements of 24 thin liquid sheets greatly accelerated the macro-mixing and the initial dispersion.The high-frequency reversing high-gravity fields promoted the mesoand micro-mixing.As a result,nano Fe3O4cores were fleetly and uniformly covered by Mn OOH precursor.As a continuously operated and static high-gravity reactor,the high-frequency impinging stream(HFIS)reactor is being developed to the large-scaled and low-cost production of various nanocomposites.展开更多
The effects of Ce doping on the structure,optical,oxidation,thermal and magnetic properties of ZnS:Ce nanorods synthesized by a chemical co-precipitation method were reported.The crystalline phase transformation from ...The effects of Ce doping on the structure,optical,oxidation,thermal and magnetic properties of ZnS:Ce nanorods synthesized by a chemical co-precipitation method were reported.The crystalline phase transformation from cubic to hexagonal structure was observed upon doping ZnS with Ce.Magnetic measurements showed the existence of room temperature ferromagnetism in Ce-doped ZnS nanorods.X-ray photoelectron spectroscopic(XPS)measurements provided evidence for Zn-S bonds and oxidation state of Ce in the near-surface region.Raman spectrum provided evidence for the presence of defects as well as hexagonal structure of 5 wt.%Ce doped ZnS nanorods.Ce substitution induced shape evolution was studied by using TEM.DRS spectra further validated the incorporation of Ce^3+ions.The present study reveals that Ce doped ZnS nanorods may find applications in spintronic devices.展开更多
基金Supported by the National Key Technology R&D Program of China(2009BAB47B08)the Key Science and Technology Project of Zhejiang Province(2008C03006)+1 种基金the Education Office Project of Zhejiang Province(Y201225412)the Technical Innovation League Project of Zhejiang Province for Seawater Desalination(2011LM301)
文摘Well-defined Fe3O4/Mn OOH nanoparticles with 61.1 emu·g-1in magnetization intensity and 90.53 m2·g-1in surface area have been synthesized by a new-style of high-frequency impinging stream(HFIS)reactor.In this reactor,two streams first collided together to form nano Fe3O4suspension,which subsequently flew through an S-shaped main channel to generate high-frequency reversing high-gravity fields.At the same time,24 thin liquid sheets impinged into the main channel at the frequencies higher than 100 Hz to create nano Fe3O4/Mn OOH colloids.The obtained powders were characterized by transmission electron microscopy/energy dispersive spectrometer(TEM/EDS),X-ray diffraction(XRD),Brunner–Emmet–Teller(BET)and vibrating sample magnetometer(VSM).Experimental results indicated that low coating ratio prolonged the induction period of heterogeneous nucleation.The high-frequency impingements of 24 thin liquid sheets greatly accelerated the macro-mixing and the initial dispersion.The high-frequency reversing high-gravity fields promoted the mesoand micro-mixing.As a result,nano Fe3O4cores were fleetly and uniformly covered by Mn OOH precursor.As a continuously operated and static high-gravity reactor,the high-frequency impinging stream(HFIS)reactor is being developed to the large-scaled and low-cost production of various nanocomposites.
文摘The effects of Ce doping on the structure,optical,oxidation,thermal and magnetic properties of ZnS:Ce nanorods synthesized by a chemical co-precipitation method were reported.The crystalline phase transformation from cubic to hexagonal structure was observed upon doping ZnS with Ce.Magnetic measurements showed the existence of room temperature ferromagnetism in Ce-doped ZnS nanorods.X-ray photoelectron spectroscopic(XPS)measurements provided evidence for Zn-S bonds and oxidation state of Ce in the near-surface region.Raman spectrum provided evidence for the presence of defects as well as hexagonal structure of 5 wt.%Ce doped ZnS nanorods.Ce substitution induced shape evolution was studied by using TEM.DRS spectra further validated the incorporation of Ce^3+ions.The present study reveals that Ce doped ZnS nanorods may find applications in spintronic devices.
