Preparation of Nano Ferrite Particle Preparation of Nano Ferrite Particle by Chemical Way in High Static by Chemical Way in High Static

Magnetic Field(HSMF)Magnetic Field(HSMF)

Yunbo Zhong, Li Zhihua, Zhongming Ren

Shanghai University

Process of Material in HSMF

HSMF

Organic or Biological Material

Metallic Material

Inorganic Non-metallic Material

Nano-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

1. Will Magnetic Field Effect the Process of Chemical Reaction?

2. Will Magnetic Field Effect the Process of Sediment/nucleation of Nano Particle?

3. Will Magnetic Field Effect the Growth of the Nano Particle?

4. Will Magnetic Field Effect the Performance of Nano Material?

Why select FerriteWhy 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 ExperimentEquipment for Experiment

Nitrogen

Mixture of Iron Nitrate, Manganese Nitrate and Zinc Nitrate SolutionAmmonia

Thermocouple

PID TemperatureController

Water-cooling Pipe

Superconductive Coil

HeaterBufferSolution

Heat Resistant Fibre

Quartz Pipe

Superconductive Magnet

pH MeterpH Probe

0

1

2

3

4

5

6

7

8

9

10

11

12

-30

-28

-26

-24

-22

-20

-18

-16

-14

-12

-10

-8 -6 -4 -2 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30

Distance to Center cm，

Mag

netic

Flu

x D

ensi

tyT

，

-500

-400

-300

-200

-100

0

100

200

300

400

500

-30 -20 -10 0 10 20 30

Distance to Center cm，

BdB/dz

T，

2 /m

Distribution of MFD inDistribution of MFD inHigh Static Magnetic FieldHigh Static Magnetic Field

Flow Chart of ExperimentalFlow Chart of Experimental

Co-Precipitation

Filtration

Abstersion

Drying

SEM 、 TEM

(Fe 、 Mn 、 Zn)NO3

Mixture

NH4HCO3 Solution

Ammonia Liquid

Control pH

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

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

Effect of temp. on Shape of sedimentEffect of temp. on Shape of sediment

40℃

B=10T 、 Adding time of reactant solution=6hrs 、 pH ＝ 7 ～ 8

50℃

60℃ 70℃

*ln

2

C

CKT

rP

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;

2hrs 6hrs

10hrs

B=10T 、 Temp=60℃ 、 pH ＝ 7 ～8

Adding time of reactant solution

Effect of Adding time of reactant Effect of Adding time of reactant solution on Shape of sedimentsolution on Shape of sediment

Effect of MFD on Shape of sedimentEffect of MFD on Shape of sediment

B=0.3T B=0.5T

B=0.6T Temp=60℃ 、 Adding time of reactant solution=1h 、 pH ＝ 7 ～

8

B=0.7T

B=10T

Temp ＝ 80 ℃ ； t ＝ 6h ； PH ＝ 7～ 9

B=4T

Effect of MFD on Shape of sedimentEffect of MFD on Shape of sediment

SolutionAggregate Particle Claviform Particle

Without magnetic field Critical magnetic field High static magnetic field

Sketch map of the mechanism of Sketch map of the mechanism of effect of Magnetic Field on nucleation effect of Magnetic Field on nucleation

and growth of nano-particle and growth of nano-particle

Energy spectrum analysis of sedimentEnergy spectrum analysis of sediment

a

c

b

d

  IronAtomic%

MaganeseAtomic%

ZincAtomic%

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-BlockParticle

22.75 5.85 0.03 3.889 758.33

d-BlockParticle

22.91 5.08 0.66 4.51 34.71

Composition of Particles

X-ray diffraction spectrumX-ray diffraction spectrum

Main Phase Composition of ParticleMain Phase Composition of Particle

Zinc FerriteManganese Trioxide

Iron Trioxide10T

NoneManganese Tetroxide

Iron Tetroxide0T

ZincManganeseIron

TEM Image of Non-ClaviformTEM Image of Non-Claviform ParticleParticle

Bright Image Dark Image

Electron Diffraction Image

TEM Image of Claviform ParticleTEM Image of Claviform Particle

Next Step Work

Fibre Nano Particle

Alignment in HSMF

Sintering

Performance Measurement

ConclusionsConclusions

1. 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;

2. The claviform particle by HSMF shows the structure of crystal, while the polygonal particle is the mixture of non crystal and crystal;

3. 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