Yunbo Zhong, Li Zhihua, Zhongming Ren Shanghai University Preparation of Nano Ferrite Particle by Chemical Way in High Static Magnetic Field(HSMF) Yunbo Zhong, Li Zhihua, Zhongming Ren Shanghai University

Process of Material in HSMF Metallic Material Nano-Material HSMF Inorganic Non-metallic Material Organic or Biological Material

Methods for Preparation of Nano-particle 1、High Energy Grinding; 2、Evaporation; 3、Co-Precipitation; 4、Sol-Gel; 5、Hydrothermal Preparation; 6、By Plasma; And so on…………

Several Questions About Preparation of Nano Material by Chemical Way in HSMF Will Magnetic Field Effect the Process of Chemical Reaction? Will Magnetic Field Effect the Process of Sediment/nucleation of Nano Particle? Will Magnetic Field Effect the Growth of the Nano Particle? Will Magnetic Field Effect the Performance of Nano Material?

Why select Ferrite Ferrite is widely used in electric power/electron and communication industry; Nano ferrite material has better performance; In some usage, shape anisotropy of nano ferrite will be welcome for its excellent magnetic property; How magnetic field effect the chemical reaction process is not well studied;

Equipment for Experiment Nitrogen Mixture of Iron Nitrate, Manganese Nitrate and Zinc Nitrate Solution Ammonia Thermocouple PID Temperature Controller Water-cooling Pipe Superconductive Coil Heater Buffer Solution Heat Resistant Fibre Quartz Pipe Superconductive Magnet pH Meter pH Probe

High Static Magnetic Field Distribution of MFD in High Static Magnetic Field

Flow Chart of Experimental Co-Precipitation Filtration Abstersion Drying SEM、TEM (Fe、Mn、Zn)NO3 Mixture NH4HCO3 Solution Ammonia Liquid Control pH

B=0T、Temp=80℃、Adding time of reactant solution=1hr、pH＝7～8 B=10T、temp=80℃、Adding time of reactant solution=6hrs、pH＝7～8

Effect of temp. on Shape of sediment 40℃ 50℃ 60℃ 70℃ B=10T、Adding time of reactant solution=6hrs、pH＝7～8

In Aqueous Solution, the Critical radius of New Nucleus is rp-Critical radius of New Nucleus; σ-Surface Energy between Particle and Solution; υ-Volume of Solution; K- Boltzman Constant; T-Temperature of Solution; C-Actual Concentration of Solute; C*-Saturation Concentration of Solute When Equilibium;

Effect of Adding time of reactant solution on Shape of sediment 2hrs 6hrs Adding time of reactant solution B=10T、Temp=60℃、pH＝7～8 10hrs

Effect of MFD on Shape of sediment B=0.3T B=0.5T B=0.6T B=0.7T Temp=60℃、Adding time of reactant solution=1h、pH＝7～8

Effect of MFD on Shape of sediment B=4T B=10T Temp＝80 ℃；t＝6h；PH＝7～9

Sketch map of the mechanism of effect of Magnetic Field on nucleation and growth of nano-particle Solution Aggregate Particle Claviform Particle Without magnetic field Critical magnetic field High static magnetic field

Energy spectrum analysis of sediment b c d

Composition of Particles   Iron Atomic % Maganese Zinc Fe:Mn Fe:Zn a-Claviform Particle 14.19 17.72 1.30 0.8 10.91 b-Claviform Particle 21.14 18.30 2.32 1.155 9.112 c-Block Particle 22.75 5.85 0.03 3.889 758.33 d-Block 22.91 5.08 0.66 4.51 34.71

X-ray diffraction spectrum

Main Phase Composition of Particle Zinc Ferrite Manganese Trioxide Iron Trioxide 10T None Manganese Tetroxide Iron Tetroxide 0T Zinc Manganese Iron

TEM Image of Non-Claviform Particle Bright Image Dark Image Electron Diffraction Image

TEM Image of Claviform Particle

Performance Measurement Next Step Work Fibre Nano Particle Alignment in HSMF Sintering Performance Measurement

Conclusions HSMF will effect the nucleation of chemical sediment process, and there is a critical MFD, Above which the nucleation will grow into stick-like or fibre-like; The claviform particle by HSMF shows the structure of crystal, while the polygonal particle is the mixture of non crystal and crystal; The HSMF will not only effect the shape of sediment, but also the phase composition;

Acknowledgement This work was financial supported by Scientific & Technological Committee of Shanghai; Thankful to sino-German Center for Research Promotion for financial support to workshop

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