3 Magnetic Materials Types: Detailed Facts

This article discusses about magnetic materials types. We are all aware of magnetism and its tendency to attract metallic objects.

In this article we shall study about different types of magnetic materials. We shall also study about places where we can see magnetism daily. The types of magnetic materials will be discussed in detail in further sections of article.

• Paramagnetic materials
• Diamagnetic materials
• Ferromagnetic materials (Soft and hard)
• Ferrites (Soft and Hard)

What are magnetic materials?

Magnetic materials are those materials which have tendency to attract metals and other magnetic materials throught the force of attraction.

This force of attraction is not visible to us. But we can still explain the principle by drawing field lines across the magnet. A magnet is another name for magnetic materials. A magnet will have two poles. The field lines will start from north pole and exit from south pole of the magnet.

Do like poles attract each other?

Now we know that there are two poles of a magnet. These poles are North and South pole respectively. We also know that a magnet attracts other magnetic material.

But do same poles attract? The answer is no. If we bring a north pole of one magnet near to north pole of another magnet, the two magnets will repel each other. Similarly two south poles repel each other. Unlike poles attract each other that is North pole of one magnet wll attract South pole of different magnet.

Examples of Magnetic materials

There are different types of magnetic materials we can find around us. The examples of magnetic materials are given in the list given below-

• Iron
• Nickel
• Cobalt
• Steel
• Stainless steel
• Rare earth metals
• Aluminium
• Gold

Magnetic materials types

Broad classification of materials says that there two types of materials- Magnetic and non magnetic. But the magnetic materials themselves are further divided into sub types.

The different types of magnetic materials are given below-

Paramagnetic materials

Paramagentic materials are those materials which are very weakly attracted to the external magnetic field. Rather these materials develop their own magnetic field lines runnng in the direction of the applied magnetic field. The examples of materials that exhibit this property are- Aluminium, Oxygen, Titanium and Oxide of Iron. A thumb rule is used to determine whether a material is paramagnetic or not.

Diamagnetic materials

Diamagnetism is completely opposite to paramagnetism. Materials that exhibit this property are repelled by external magnetic field and induce internal magnetic field lines that also run in the opposite direction to that of the externally applied magnetic field. The materials that exhibit this property are labelled as diamagnetic by using a simple thumb rule that was used to determine paramagnetism in materials.

Ferromagnetic materials (Soft and Hard)-

Ferromagnetic materials are those materials which give very strong response to magnetic field of same direction. There are two types of ferromagnetic materials they are-

• Soft– As the name suggests, soft ferromagnetic materials are permeable. They have less coercive force, they can be magnetized and de magnetized without much difficulties. They also have a low hysterisis curve. The materials that exhibit soft ferromagnetism are Iron, Nickel, Aluminium, Tungsten and Cobalt.

• Hard– These materials are opposite to that of soft ferromagnetic materials. These materials have very low permeability. The process of magnetizing and de magnetizing these materials is also very cumbersome and complicated. The materials which exhibit this property include Cobalt Steel, Nicke;, Alloys of Cobalt and Aluminium etc.

Ferrites (Soft and hard)

Ferrite are a group of materials that show properties between ferromagnetic and non ferromagnetic materials. Like ferromagnetic materials, they are also classified into two types, they are-

• Soft– Soft ferrites show very high resistance properties with a hysterisis curve in a shape of square. The range of their resistivity lies near around 109 ohm-cm. The properties exhibited by these materials are favourable to be used in microwaves which uses high frequencies. The manufacturing of ferrites is done by mixing oxides in powdered form and then condensing and sintering at very high temperatures.

• Hard– These materials have a hexagonal shape and they have a very high density. These materials are used in applications which need very high strength for example door latches, toys and door closer.

What are magnetic field lines?

These lines are hypothetical in nature and do not exist in real life. These are imaginary lines drawn to indicate the movement of Magnetic North Pole.

The area where these lines are said to exist is called as magnetic field. Any magnetic material when comes inside this field gets attracted. Magnetic field can be said to be a vector quantity due to presence of both magnitude and direction. We can determine the strengths of the magnets with the help of magnetic field. 

Image credits: Wikipedia

Properties of magnetic field lines

The properties of magnetic field lines are given below-

• It is a vector quantity – A vector quantity is that quantity which has both magnitude and a direction.
• Direction of field lines – The magnetic field lines emanate from magnetic North Pole and move towards the magnetic South Pole. The lines are curved for a bar magnet.
• They do not intersect each other -Thought all the field lines may appear to be curved, but no two field lines will ever intersect. They will always move without intersecting each other.

How to draw magnetic field lines using only a compass and bar magnet?

The following steps should be followed if we want to draw magnetic field lines using only a magnetic compass and a bar magnet-

• First we take bar magnet and a magnetic compass.
• Then we put the North pole of the magnet near the compass
• Then we mark a dot at the point where compass pointer points the direction. Mark this as point X.
• Now we put other end of the compass at point X.
• Again we mark a dot where the compass pointer points. We mark this point as Y
• We keep repeating this process until south pole of the magnet is reached.
• After connecting these dots we will see curved lines coming from one end and going towards another. These curved lines are called as field lines.

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