# Difference between a ferromagnet and a paramagnet?

• ultimateguy
In summary: Ferromagnets are permanent magnets and paramagnets are not. This is probably the simplest and most important distinction. Ferromagnets are permanent magnets because they contain magnetic dipoles that 'influence' other dipoles around them, allowing them to align with one another. This property results in an enhanced magnetic response, as there is a reduced random variation in dipole orientation. A paramagnet does not have this property, as the dipoles are completely random.
ultimateguy
I'm doing a presentation on magnetic hysteresis, and I have a feeling one of the profs will ask me what is the difference between a ferromagnet and a paramagnet. I haven't taken my 3rd year E&M class yet, so I would just like to know what I should answer.

Ferromagnets are permanent magnets and paramagnets are not. This is probably the simplest and most important distinction.

StatMechGuy said:
Ferromagnets are permanent magnets
Not quite true. A ferromagnet with a large remanence makes a good permanent magnet. A ferromagnet with a small remanence (ie: a soft ferromagnet) does not make a good permanent magnet.

Ferromagnets contain magnetic dipoles that 'influence' other dipoles around them, allowing them to align with one another. This property results in an enhanced magnetic response, as there is a reduced random variation in dipole orientation.

Claude.

Claude Bile said:
Ferromagnets contain magnetic dipoles that 'influence' other dipoles around them, allowing them to align with one another. This property results in an enhanced magnetic response, as there is a reduced random variation in dipole orientation.

Claude.

And how do paramagnets behave? Are the dipoles just completely random?

ultimateguy said:
I'm doing a presentation on magnetic hysteresis, and I have a feeling one of the profs will ask me what is the difference between a ferromagnet and a paramagnet. I haven't taken my 3rd year E&M class yet, so I would just like to know what I should answer.
In a paramagnet, the magnetization (M) is can be given as M=\chi H where
\chi is positive. In a ferromagnet, M and H are almost unrelated, and M is much larger than H in magnitude. The use of \chi in ferromagnetism is meaningless, altough some engineers try to use it.

Last edited:

## 1. What is the main difference between a ferromagnet and a paramagnet?

Ferromagnets have a strong spontaneous magnetization that does not disappear even in the absence of an external magnetic field, while paramagnets only show magnetization in the presence of an external magnetic field.

## 2. How do the magnetic properties of ferromagnets and paramagnets differ?

Ferromagnets have a high magnetic susceptibility, meaning they can easily be magnetized and retain their magnetization even after the external magnetic field is removed. Paramagnets, on the other hand, have a low magnetic susceptibility and their magnetization disappears when the external magnetic field is removed.

## 3. Can you give an example of a ferromagnet and a paramagnet?

A common example of a ferromagnet is iron, while a common example of a paramagnet is aluminum. Other examples of ferromagnets include cobalt and nickel, while paramagnets include copper and gold.

## 4. How do ferromagnets and paramagnets respond to temperature changes?

Ferromagnets have a Curie temperature, above which they lose their ferromagnetic properties and become paramagnetic. On the other hand, paramagnets become more strongly paramagnetic as the temperature decreases.

## 5. What is the cause of the difference in magnetic properties between ferromagnets and paramagnets?

The difference is caused by the alignment of electron spins within the materials. In ferromagnets, the electron spins are aligned in the same direction, creating a strong magnetic field. In paramagnets, the electron spins are randomly oriented, resulting in a weak magnetic field.

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