Introduction
of Magnetism and Matter
Index
|
ü History
ü Definition
of Magnets and Magnetism in physics
ü Source
of Magnetism or Cause of Magnetism
ü Classes
of Magnetic Materials
ü Definition
of Matter
ü Relation
between Matter and Magnetism
ü Conclusion
|
History
In the ancient world when people started noticing that Lodestones
(magnetized pieces of mineral magnetite) was able to attract iron it was then
only when the concept of magnetism was introduced. Indian surgeon Surushastra was the first person to use magnets
for surgical purposes.
Definition of Magnets and Magnetism in physics
Magnets: The ability of an object or a material to produce
invisible magnetic field lines in order to develop a force which attracts other
ferromagnetic materials such as iron, steel, etc. are known as Magnets.
Magnetism: Magnetism is a phenomenon by
the virtue of which there develops an attracting or repulsive force between two
magnetic objects.
Source of Magnetism or Cause of Magnetism
Motion of electrons in atoms gives rise to the phenomenon called
magnetism. Basically, two types of motions are associated with the electrons:
·
Motion of electrons in an orbit within the nucleus.
·
Spin of electrons around its axis.
The spin and orbital moments imparts magnetic moment on each
electron, forcing them to behave as tiny magnets.
The rotational force experienced by a magnet when placed in a
magnetic field perpendicular to its magnetic axis is defined as the magnetic
moment of a magnet.
Classes of Magnetic Materials
The magnetic behavior of materials can be classified in the
following groups:
· Diamagnetism: Those materials which are less susceptible to
the magnetic fields are known as Diamagnetic Material and
they exhibit a property called diamagnetism, whereby the net magnetic moment of atoms is zero. Thus, when placed in
a magnetic field it produces negative magnetization. For Example: Water, Wood.
· Paramagnetism: The best example of paramagnetic
material is aluminum and platinum. Due to partially filled orbital, some atoms
possess net magnetic moments, resulting in positive magnetization and
susceptibility in the presence of magnetic field. But when the field is
removed, the magnetization is zero. For Example: Magnesium, Molybdenum.
· Ferromagnetism: Unlike diamagnets or paramagnets, those
materials which tend to remain magnetized even when the magnetic field is
removed exhibits ferromagnetism. This phenomenon is also known as Hysteresis and the plot between variations of
magnetism with magnetic field is called Hysteresis Loop.
However, at one point or temperature the ferromagnetic materials tend to lose
its magnetic properties. This temperature or point is known as Curie point or Curie temperature. For Example: Iron, Nickel, and Cobalt.
· Ferrimagnetism: The basic difference between a ferromagnetic material and ferromagnetic material
is that some magnetic domains in ferrimagnetic material point in the same
direction while some point in the opposite direction. While in case of
ferromagnetic material all the magnetic domains point in the same
direction. For Example: Cubic Ferrites
composed of iron oxides, Aluminum, Zinc etc.
·
Anti-ferromagnetism: In anti-ferromagnetic
material, the magnetic moments of
atoms or molecules usually related to the spin of the electrons align in a
regular pattern with neighboring spins in opposite directions.
Definition of Matter
In modern physics, matter is defined as a substance which is
made of various types of particles of various size and matter each. In simple
language, substance which has mass and occupies space is known as Matter. For Example:
Hematite (main ore of iron), oxides such as nickel oxide.
Different States of Matter
There are three different states of matter:
Solid
|
Liquid
|
Gas
|
·
Solid: Substances which have definite shape and volume, high density
and are not easily compressible are defined as Solid. The inter-molecular
attraction (forces that operate within the particles such as atoms, ions etc.)
in solid is very strong and it holds the particles of the substance close to
each other.
·
Liquid: Substances which have indefinite shape (takes the shape of a
container easily) is known as Liquid. Liquid
substances have density less than solids but much higher than gases and they
are largely compressible. Unlike solids, the inter-molecular attraction between
the particles of liquid are weak and the particles are less tightly held.
Hence, they are allowed to move away from each other.
·
Gas: The Substances which have indefinite shape and has low density
are categorized as gaseous substance. They have indefinite volume and are
highly compressible. Also, the inter-molecular forces between the particles inside
a gaseous material are very weak compared to that of liquid and gas.
The role of the forces existing between the particles within the
substance determines how the substance will behave when placed in Magnetic
field. Normally every substance possesses magnetic characteristics. Substances
like copper and aluminum which is considered to have high magnetic property is
also affected when placed in a magnetic field. Depending on the response of
their behavior that is, either attraction or repulsion matters are classified
as paramagnetic or diamagnetic respectively.
Conclusion
Magnetism is a common and very important phenomenon which finds
use in every field. In physics, Magnetism helps to understand the behavioral
property of matter. The way a matter responds when placed in magnetic field
gives rise to different types of magnetic materials like paramagnetic or
diamagnetic as explained above. Thus, it can be concluded saying that matter
and magnetism phenomenon is closely related to each other.
Frequently asked Questions (FAQs)
Q1. Who discovered the Magnet?
Sol. Magnet was discovered by ancient Greeks who started noticing
that magnetized pieces of mineral Magnetite were able to attract iron.
Q2. What is the source of Magnetism?
Sol. Every material when placed inside a magnetic field exhibit
magnetism because of the arrangements of electrons and their motion inside the
matter. Motion of the electrons can be categorized into two parts:
·
Motion of electron around the nucleus.
·
Spin of electron around its Axis.
Q3. What is Magnetism in physics?
Sol. In physics, Magnetism is defined as the property
by the virtue of which a magnetic material is able to create an attraction or
repulsion force. In physics, Magnetism helps to study the behavior of matter in
magnetic fields.
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