Hi guys,

Probably a year 8 physics question.

But
When a magnet is cooled does it's attractive/repulsive strength increase? Is the inverse also true in that the magnetism weakens as it gets hotter?

If so is there a ratio worth mentioning?

Any one?

Its true that a magnet will de-nature after a certain amount of heat energy is applied to it (coz the thermal motion of atoms overcomes the strict magnetic alignment of the magnet).

I dont know what happens with cooling though or whether there is a linear relationship between a magnets strength and heat applied before the denaturisation point.

How to make a permamagnet.

Take some iron.
Melt it
Put into a mould still melted, then in a really strong moment so that all the magnetic dipoles line-up
Cool it so it solidifies, all the dipoles remain frozen in place.

No, magnetism is not directly related to temperature, but all magnetic materials have a (often sharp and well-defined) temperature, above which they loose their magnetic properties. For non-magnets, the process is fully reversible, that is, when cooled below this point, they regain their full magnetic properties. For permant magnets, the process is partly or totally irreversible, depending on type.

Hans

I remember that temperature limit above which ferromagnetic material loses its magnetism is called Curie Temperature.

I am not sure about the relationship between temperature and magnetism below Curie Temperature.

Paul T

Let me remember.... we have already discovered Super-conduction phenomenon..... Since electricity and magnetism are related somehow, there may be super-magnetism as well.... But how to explain it?

Curousicty,

What a good idea....super magnets.....

I think I forgot to include my theory on why it would be harder to explain supermagnetism, if existing, than to explain super-conductivity. But correct me anyway:
In super-conduction: Since very cold object has its atoms/molecules line up almost straight and move/vibrate little, electrons can pass through the object very easily as if they were shoot in vacuum.
Anyone care to share a theory?

Superconductivity means (virtually) zero resistance. What would supermagnetism imply?

Curie temp, RIGHT, thank you! :)

Hans