Ferrimagnetism vs ferromagnetism

[username327]

Hello All,

I am trying to learn about the diffrerent types of magnetism and would like to know how we can tell the difference between ferri- and ferromagnetism? Are their any measurements which can distinguish unequivocally between the two types?

Thank you for any help

 

[pallidin]

From: http://en.wikipedia.org/wiki/Ferrimagnetism

In physics, a ferrimagnetic material is one in which the magnetic moments of the atoms on different sublattices are opposed, as in antiferromagnetism; however, in ferrimagnetic materials, the opposing moments are unequal and a spontaneous magnetization remains. This happens when the sublattices consist of different materials or ions (such as Fe2+ and Fe3+).

Ferrimagnetism is exhibited by ferrites and magnetic garnets. The oldest-known magnetic substance, magnetite (iron(II,III) oxide; Fe3O4), is a ferrimagnet; it was originally classified as a ferromagnet before Néel's discovery of ferrimagnetism and antiferromagnetism in 1948 [1].

Some ferrimagnetic materials are YIG (yttrium iron garnet) and ferrites composed of iron oxides and other elements such as aluminum, cobalt, nickel, manganese and zinc.

 

[username327]

Hello pallidin,

Thanks for the quick reply.

Ok so let's assume we are talking about an Fe-oxide for which we don't have any knowledge of the proportions of Fe3+ and Fe2+ but we want to know which type of magnetism it exhibits. Is there a measurement of its magnetic properties we can make which will differentiate between ferri- and ferro? (I know that by implication ferri => some Fe2+)

Thanks

 

[pallidin]

Thanks. Wish I had more knowledge on this subject.
Perhaps an expert can jump-in and elucidate.

 

[sardar]

!

Hello there,

Ferromagnetism and ferrimagnetism are two types of permanent magnetism that occur in certain materials. The main difference between these two types is the arrangement of atomic magnetic moments within the material.

In ferromagnetic materials, the atomic magnetic moments are all aligned in the same direction, resulting in a strong overall magnetic field. This alignment can be maintained even after an external magnetic field is removed, making these materials excellent permanent magnets.

On the other hand, in ferrimagnetic materials, the atomic magnetic moments are arranged in two different directions, with one direction being stronger than the other. This results in a weaker overall magnetic field compared to ferromagnetic materials. Additionally, in ferrimagnetic materials, the alignment of the magnetic moments can be easily disrupted, making them less suitable as permanent magnets.

To distinguish between ferromagnetism and ferrimagnetism, one can measure the magnetic properties of the material, such as its magnetic moment, magnetic susceptibility, and coercivity. Ferromagnetic materials typically have a higher magnetic moment and coercivity compared to ferrimagnetic materials.

There are also other techniques, such as neutron scattering and magnetic resonance, that can provide more detailed information about the magnetic structure and help distinguish between ferromagnetic and ferrimagnetic materials.

I hope this helps in your understanding of these two types of magnetism. Let me know if you have any further questions.