ASHISH MANISHA KUSUM
ASHISHMANISHAKUSUM
Bismuth ferrite Nanoparticles
Bismuth Ferrite
Rhombohedral Structure.
Multi-ferroic.
Curie temperature(tc=825 c)
Neel tempreature (tN=360 c)
MULTIFERROICS (Definition)
Materials that simultaneous exhibit two or more ferroic
properties in the same phase.
Ferroelectric(anti) Ferromagnetic(anti) Ferroelastic(anti)
Advantages of BFO Nano ParticlesUsed in
Memory Devices
Telecommunication
Sensors
Synthesis of BFOSynthesis refers to a combination of two or more
entities that together form something new.
Two approaches Top-down Bottom-up
TOP - DOWNBOTTOM - UP
Breaking Down Matter into more basic building blocks.
Fabrication is often more easily
A lot of material is wasted
Used in Fibres.
Useful in making large scale nanostructure.
Building up complex systems by combining Simple atomic level
components.
Limitations in how big structures can be made
This approach leads to less wastage.
Approach Used currently.
Nature use this approach.
Sol-Gel method-introduction
Method in which solid particles are dispersed in Liquid(sol) and
together they form a 3-D network extending throughout the
liquid(gel).
Involves hydrolysis.
Low temperature process.
By this, we get amorphous nano crystals.
Being a Bottom-Up approach, this method is cost effective.
Steps Involved in typical Sol Gel Method
Hydrolysis
Condensation
Gelation
Ageing
Drying
Chemicals Required
Distilled Water 90 ml
Bismuth Nitrate 4.04g
Iron nitrate 4.8507g
Nitric acid 20 ml
Citric acid 3.8424 g
Synthesis Flow ChartDistilled WaterMixed SolutionBismuth
nitrateCitric Acid+Iron Nitrate Solution
Heating Under Vigorous StirringAuto CombustionBrownish Viscous
ResinBrown Powder is formedCalcinated
Nitric acid
Observations
1234SOL
GEL
AUTO COMBUSTION
GRINDED
Advantages of SOL - GEL MethodCheap Method
Homogeneous Compound can be achieved.
Very small particle size can be obtained.
Low operating temperature .
CharacterizationCharacterization refers to the study of
materials features such as its composition, structure,& various
properties like physical, electrical, magnetic etc.
In our experiment , we use X-Ray Diffraction method to study the
crystal structure of BFO nano particles obtained.
X-rays Consists of high Energy Photons (em waves).
EM radiation with wavelength from 0.01 nm to 10 nm falls into
category of X- ray.
K.E. of a moving electron is converted into a photon.
Inverse Photoelectric effect.
Unaffected by Electric and Magnetic fields.
Faster the electron, more penetrating resulting X-rays.
Greater the number of electrons, greater intensity of X-ray
beam.
X-ray Diffraction
XRD can be used to look at various characteristics of the single
crystal or
polycrystalline materials using Braggs Law ,
n = 2d sin
Powder Method
is fixed, radiation is variable.
Specimen consist of million of powder particles, each oriented
randomly in space.
X-Ray Characterstic RadiationTarget Wavelength (A)
Mo 0.71
Cu 1.54
Co 1.79
Fe 1.94
Cr 2.29
For Hexagonal Lattice
Where and
Observation
Observations Continued..
a = 5.880 nm c = 139.040 nm
v = 376 (A)^3
These values are given by JCPDS cards.Number of atoms in a unit
cell can be calculated
and found to be 6.
From Debye Scherrer Formula
D = Crystalline size
= wavelength of X-ray used
= peak width
= angle at maximum intensity peak
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Result and Discussion
We have prepared Bismuth Ferrite Nano particles using electro
spinning method.
Nano particles were heated at 400 c temperature in order to get
pure phase.
Crystalline size is found using Debye Scherrer formula= 33.87
nm.
Prepared nano particles were characterized by XRD.
The results are in concurrence with existing literature.
Nanoparticle-based technologies cover different fields of
science.
Nanoparticles, are key components in the development of new
advanced technologies.Nanoparticle characterization is necessary to
establish understanding and control of nanoparticle synthesis and
applications.
Acknowledgements
Special Thanks to ::: Prof. Binay Kumar sir Abhishek sir Harsh
sir (P.hD. Scholar) Abid sir (P.hD. Scholar) Sanjay sir (P.hD.
Scholar)
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