This document discusses magnetic nanoparticles and their properties. It defines nanoparticles as between 1-100 nm in size and explains how their small size affects magnetic properties. For example, ferromagnetic nanoparticles smaller than 10 nm can change magnetic orientation via thermal energy, making them unsuitable for data storage. The document also describes different types of nanoparticles like soft and hard, and how they are classified based on dimensionality. Magnetic properties are explained in terms of spin exchange interactions and how nanoparticles can exhibit superparamagnetism due to their small size.

1. EXPERIMENT NAME:
Measurement of magnetic moments of nano particles using theoretical
approach.
INTRODUCTION:
A nanoparticle or ultrafine particle is usually defined as a particle of matter that is
between 1 and 100 nanometres (nm) in diameter. The term is sometimes used for
larger particles, up to 500 nm, [citation needed] or fibres and tubes that are less than
100 nm in only two directions. At the lowest range, metal particles smaller than 1 nm
are usually called atom clusters instead.
Being much smaller than the wavelengths of visible light (400-700 nm), nanoparticles
cannot be seen with ordinary optical microscopes, requiring the use of electron
microscopes or microscopes with laser.
Ferromagnetic and ferroelectric effects
The small size of nanoparticles affects their magnetic and electric properties. For
example, while particles of ferromagnetic materials in the micrometre range are
widely used in magnetic recording media, for the stability of their magnetization
state, those smaller than 10 nm can change their state as the result of thermal
energy at ordinary temperatures, thus making them unsuitable for that application
Magnetic nanoparticles
Magnetic nanoparticles have varied applications ranging from data storage to
diagnostic applications such as clinical imaging. These nanoparticles are
manipulated by the use of magnetic field. For instance, ferrite nanoparticles with a
size smaller than 128nm become superparamagnetic thereby preventing self-
agglomeration. The stability of ferrite nanoparticles in a solution can be increased by
modifying their surface using surfactants, or derivatives of phosphoric acid or silicon.
However, the magnetic property of nanoparticles can also be of disadvantage in
certain situations. For example, ferroelectric materials smaller than 10 nm can switch
their magnetization direction using room temperature thermal energy, thus making
them unsuitable for memory storage.
THEORY:
Softmagnet;
Those materials that can magnetized and demagnetized easily called soft magnet.

3. Hard magnet;
Those materials that cannot magnetized and demagnetized easily called hard
magnet.
Hard nanoparticles
These nanoparticles impart their properties to polymers. Clay nanoparticles, when
incorporated into polymer matrices, increase reinforcement leading to stronger
plastics. Hard nanoparticles have also been used in textile fibres to create smart and
functional clothing.
SOFT NANOPARTICLES.
Of the many semi-solid and soft nanoparticles that have been manufactured,
liposomes are of particular significance. Various types of liposome nanoparticles are
used clinically such as delivery systems for anticancer drugs, antibiotics, antifungal
drugs, and vaccines.
Ferromagnetic and ferroelectric effects
The small size of nanoparticles affects their magnetic and electric properties. For
example, while particles of ferromagnetic materials in the micrometre range are
widely used in magnetic recording media, for the stability of their magnetization
state, those smaller than 10 nm can change their state as the result of thermal
energy at ordinary temperatures, thus making them unsuitable for that application.
Types of Nanoparticles
Nanoparticles are classified as 0-Dimensional (D), 1D, 2D, or 3D depending on their
overall shape.
1-D nanomaterials
1-D nanomaterials have thin films or surface coatings and are used in the circuitry of
computer chips and for anti-reflective properties and hard coatings on eyeglasses.
These have been used in electronics, chemistry, and engineering.
2-D nanomaterials
2-D nanomaterials have fixed and long nanostructures with thick membranes. They
are used to prepare nanopore filters used for small particle separation and filtration.
Asbestos fibre is an example of 2D nanoparticles.

5. 3-D nanomaterials
3-D nanomaterials are fixed and small nanostructures where thin films are deposited
under conditions that generate atomic-scale porosity, colloids, and free nanoparticles
with various morphologies.
Magnetic properties of nanoparticles:
Each spin is small magnet.
Interaction with neighbouring spins is dominated by the spin exchange interaction.
Exchange integral.
Exchange integral is also called the exchange energy this is responsible for the
ferromagnetism in the material.
It is the phenomenon in which the individual magnetic moment will attempted to
Alling all other atomic moment with in a magnet rial with in itself.is known as
exchange integral,
In the classical view of Heisenberg represent this coupling b/w two nearest spins by
an expression given bellow.
𝐸𝑒𝑥 = −2𝐽𝑠𝑖𝑠𝑗
Were,
J is the exchange integral.
𝑠𝑖𝑠𝑗 are two neighbouring spin.
 If j is positive, it indicates the material exhibits ferromagnetic behaviour and
the exchange energy is at minimum when two neighbouring moment are in
parallel alignment.
 If j is negative, it indicates the material exhibits antiferromagnetic behaviour
and the exchange energy is at minimum when two neighbouring moment are
in parallel alignment.
I think of the superparamagnetic as a small ferromagnet. because of its small size,
the magnetic moment rotates when the the external field is applied.
Like the paramagnet the superparamagnetic return to zero magnetization when the
field is removed.it is due the small in size not intrinsically weak exchange between
the individual moment.
Nano scale has a big impact on the magnetic properties.
In a normally ferromagnetic material, nano scale reduced the moment, but it can be
restored by Appling a magnetic field.