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Thread: how do scientists demagnatize metal?

  1. #1 how do scientists demagnatize metal? 
    Forum Freshman
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    what makes metal magnetic? the fact it can easly go positive in charge?
    what happens to make them non magnetic, such as in the large hadron collider?


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  3. #2  
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    I assume by "magnetic", you mean ferromagnetic?

    If a material (doesn't have to be a metal) contains elements which tend to show ferromagnetic behaviour, such as nickel, iron, cobalt, it might be ferromagnetic. Another factor is the microstructure of the material. An example of this is steel: austenitic steel (e.g. most common stainless steels) are not attracted to magnets, while martensitic (e.g. hardened steel) or ferritic steels are. The main difference between those steels is microstructure (the composition is also a bit different, because the composition partially determines the preferred structure).

    I don't know what you mean by the ability to go positive in charge.

    The two easiest ways that I know of to demagnetise a material are:
    1) temperature: in a magnet, little magnetic fields are "frozen" in space to all point in the same direction. Given enough energy, they'll vibrate to random directions, and the sum will be zero.
    2) decreasing alternating magnetic field: put the magnet inside a coil. A strong current through the coil will magnetise the magnet. Reverse the current and the magnetisation of the magnet will reverse. If you repeat this process while slowly decreasing the magnitude of the current, eventually the remaining magnetisation will be zero.


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  4. #3  
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    okay thanks!

    so what causes a material to be magnetic? is it just that the material is an ion?
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  5. #4  
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    No, it has to do with some quantum physical effects. Wikipedia can explain it better than I can.
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  6. #5  
    Time Lord
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    In Moby Dick an electrical storm permanently reverses all the ship's compasses. Captain Ahab then hammers an upright sewing needle on broken iron, to charm it magnetic for the superstitious crew to witness.

    Chapter 124. The Needle

    Possible?
    A pong by any other name is still a pong. -williampinn
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