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Author Topic: Can a powder make a powerful magnet?  (Read 1494 times)

Offline Not-a-scientist

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Can a powder make a powerful magnet?
« on: 13/10/2015 04:24:11 »
What is the most powerful magnetic powder in the world is and is it capable of attracting a small object from a distance of upto 3 meters away to it?

I realise that the answer to this might be obvious but im new here.
« Last Edit: 14/10/2015 08:01:36 by chris »


 

Offline wolfekeeper

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Re: Magnetic Powder Power?
« Reply #1 on: 14/10/2015 01:26:49 »
???? Powder is usually poorly magnet; most magnets are solids.

A pile of powdered iron will attract a small magnet from quite a distance, but not at all strongly.

A pile of powdered neodymium or other hard magnetic material will probably not do so significantly, it will tend to arrange itself to cancel itself out
 
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Offline evan_au

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Re: Can a powder make a powerful magnet?
« Reply #2 on: 14/10/2015 21:41:19 »
Neodymium magnets are quite strong, and they are formed from a powder which is rapidly cooled - the temperature is dropped by millions of degrees per second to "freeze in" a metastable structure. Obviously, this cooling does not continue for anywhere near a second!

Then a strong external magnetic field is applied while slowly cooling the material down through the Curie temperature, "freezing in" the external magnetic field in the orientation of the atomic-level magnetic fields.

As for attracting objects from several meters away, the mass and friction of an iron or other magnetic object would prevent it moving closer to the magnet, unless it were mounted on an air-hockey puck. It would probably work OK in the International Space Station, in a microgravity/microfriction environment.

You really need a superconducting magnet to attract objects from meters away in Earth's gravity. Some types of superconducting wire are manufactured from a powder, but the magnetic field is generated by the supercurrent, not by the wire itself.

See:
...but do not try this when you go for an MRI!
 
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Offline diethyl

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Re: Can a powder make a powerful magnet?
« Reply #3 on: 15/10/2015 08:39:57 »
But look from the large magnetic field- universe, much powder make a powerful magnet.
 

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Re: Can a powder make a powerful magnet?
« Reply #3 on: 15/10/2015 08:39:57 »

 

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