Question about magnets and electromagnets/ism

[Guest bobbydigital]

I am a bit confused about the concept of magnets. It is said that magnets attract opposites, and repel likes. Now does that refer to the material, or a magnet being attracted/repelled by another magnet?

 

Also...

 

If an electromagnetic apparatus is strong enough, will attract/pull just about any type of matter? What are the conditions for a certain type of material to be pulled in by electromagnets?

 

Thanks in advance.

 

The reason I was wondering this is because I recently read Angels and Demons, and in it antimatter is created, kept in a vacuum sealed device, and is held by a group of powerful electromagnets. Althought it is a work of fiction, antimatter has actually been created in a lab by CERN.

[Primarygun]

If an electromagnetic apparatus is strong enough, will attract/pull just about any type of matter? What are the conditions for a certain type of material to be pulled in by electromagnets?

Yes, I think they will.

Strong electrostatics forces between a charged substance can repel or attract electron from a substance.

If the force is moderate enough, the electron would not be pulled away or stay at the position, instead the whole substance moves.

[ed84c]

Magnetic materials are so due to electron spin, as all electrons spin i guess so. Can anybody explain electron spin in terms of waves?

[swansont]

When you speak of "opposites attract, likes repel" it usually indicates ferromagnetism, aka "permanent" magnets. Ferromagnetism in materials is due to unpaired electron spin. Not all materials have unpaired electrons, and most materials are not ferromagnetic.

 

Ferromagnetism isn't the only type. There is also diamagnetism and paramagnetism.

 

Of the elements, iron, nickel and cobalt are ferromagnetic with curie points above room temperature, and gadolinium is right around room temperature. A couple other rare-earth elements are below room temp. The other types respond to external fields, either being attracted to or repelled by the external field, because of the response of the electrons to the external fields.

 

Also, antimatter has been created in a lot of places other than CERN. And trapping ions or charges is pretty trivial. Even neutral atoms, under the right conditions, can be stored in magneto-optic or magnetic traps.

[ed84c]

Is antimatter not created every time you switch on an LED?

[cyeokpeng]

It refers to only materials capable of producing magnetic field around them, such as paramagnetic materials like cobalt and nickel, correct me if I'm wrong cos I m too a little bit confused about the concept of paramagnetism, diamagnetism and ferromagnetism. Only a certain class of materials produces intrinsic magnetic field around them and they form your natural magnets.

 

As for iron, they are ferromagnetic and this means than only if magnetic field from other sources is nearby, they will be able to exhibit orientation of tiny magnetic cells or regions such that they aid in the magnetic field. Also, they have the ability to retain the magnetism even if the external magnetic field magnetizing the iron is removed!!!

 

An important concept of magnetic field is that it exist as dipoles, meaning that if there is a North pole, there must be a corresponding South pole in the field. This does not occur for other fields like electric field in which you can have one indepedent positive charge creating a field. That is why if you break up a piece of magnet into small magnets, they will be many individual North and South poles.

 

So should answer your first question, only materials exhibiting paramagnetism and magnetized ferromagnetic materials can produce magnetic fields around it such that if like poles are put close to each other they repel and vice versa.

[TWJian]

IMHO,cobalt and nikel exhibit ferromagnetism(even though they are not iron)instead of paramagnetism.Most compunds and elements are paramagnetic.Strong paramagnetism is exhibited by compounds containing iron, palladium, platinum, and the rare-earth elements.These elements have some inner electron shells that are incomplete, causing their unpaired electrons to spin like tops and orbit like satellites, thus making the atoms a permanent magnet tending to align with and hence strengthen an applied magnetic field.Oxygen and other not -metals also exhibit paramagnetism at extremely low temperatures.You can obseve this effect in a superconductor which exhibit diamagnetism.The extreame cold temperatures will cause the thermal acticity atoms of the liquid nitrogen to decrease,therefore rendering it magnetic.

[swansont]

Is antimatter not created every time you switch on an LED?

 

Not as far as I know. What reaction or particles did you think would occur/appear?