Magnet Myths and Misconceptions

[TinselKoala]

If a feromagnetic object is placed between two like pole's then it will not be stable and be repelled away,as it will not be attracted to two like charges. If the poles have opposite charges(north/south as we are calling them)then the feromagnetic material will be stable.

Oh come on now. Think about what you have posted. Get some magnets out and play with them. You will _never_ be able to get a ferromagnetic object to stay in a stable position between two unlike poles of permanent magnets, without active (electromagnetic, sensed, feedback loop) stabilization, or mechanical contact. The object will always run over and attach to one or the other of the poles. 
And if you have two like poles, the same thing happens, the object will happily be attracted and will wind up stuck to one of the poles, or if it is big enough, both of them.

Earnshaw's theorem for magnetism:
http://en.wikipedia.org/wiki/Magnetic_levitation

Earnshaw's theorem proves that using only paramagnetic materials (such as ferromagnetic iron) it is impossible for a static system to stably levitate against gravity.

 

[tinman]

 
And if you have two like poles, the same thing happens, the object will happily be attracted and will wind up stuck to one of the poles, or if it is big enough, both of them.

Earnshaw's theorem for magnetism:
http://en.wikipedia.org/wiki/Magnetic_levitation

If a magnetically active material(our object) is suspended from a string above one pole of a magnet(with say a gap of 10mm),and another like pole of another magnet is brought close to that suspended object,the object will be repelled away from both magnets.

[MarkE]

Oh come on now. Think about what you have posted. Get some magnets out and play with them. You will _never_ be able to get a ferromagnetic object to stay in a stable position between two unlike poles of permanent magnets, without active (electromagnetic, sensed, feedback loop) stabilization, or mechanical contact. The object will always run over and attach to one or the other of the poles. 
And if you have two like poles, the same thing happens, the object will happily be attracted and will wind up stuck to one of the poles, or if it is big enough, both of them.

Earnshaw's theorem for magnetism:
http://en.wikipedia.org/wiki/Magnetic_levitation

True:  But consider that we make up a really big C core with nicely lapped finish on the facing poles, and a winding around its back.  Let's say 50mm x 50mm faces separated by 2.5mm.  We set the core on its back with the opening in the C facing up.  Next we glue a 1mm x 1mm x .25mm thick ferrite to the end of a 2mm wide by 0.1 - 0.2 mm thick x 80 mm long piece of PET.  We suspend that from a fixture that allows us to locate the ferrite inside the C core opening where we can move from left to right across the gap, and up and down within the gap.

Experiment 1:  Power the winding.  Play "Operation insert probe".  Every effort to insert the probe from above will fail with the probe getting stuck to one pole or the other

Experiment 2:  With the winding powered off, insert the probe dead center vertically and laterally in the gap.  The fixture will be able to move the probe within the gap across the gap's length.  Verify that this is so with the power off.  Next repeat with the power on.  Note the deflection on the PET suspension moving back and forth.  Does the probe still snap to each pole?

[tinman]

Even soft iron has come finite coercivity and will retain some magnetization after the external field is removed.
But for practical purposes this remanent magnetization is almost zero in modern soft ferrites.
...but how does it reach out and grab the flux in the space around it then?
If it isn't magnetized then you'd have to throw away the entire magnetic domain theory and observations with Kerr microscopes, etc...

The magnetic modle theory is incorrect,and my theory stands.
If the positively charged end of a magnet is bought into contact with a magnetically active material(eg.iron/steel),then the negatively charged particles within that material will seek(be attracted to) the positively charged particles at the end of the magnet.

If you take a magnet and a piece of steel that has a low charge separation factor(easly magnetised)eg.a screwdriver,and a compass,we can see this charge separation happen. If you use say the positively charged end of your magnet(and we are calling this the north field),and you stroke the tip of your screwdriver with it,the negatively charged particles will be pulled to the tip of the screwdriver,as they are attracted to the positively charge end of your magnet. When you check to see what field the tip of your screwdriver now has with your compass,it should show the opposite field to that of the magnet pole you use to magnetise your screwdriver.

[picowatt]

All magnetically active materials have a neutral charge(an even amount of positively and negatively charged particals throughout the object). Each pole of a magnet has only one charge-one pole positive and one pole negative,and each of these is attracted to a neutral charge(our magnetically active object) Depending on the material will depend on how well the object retains it's neutral charge through the mass of the object when the induced external charge(magnetic field) is removed. Some materials can achieve charge separation quite easly(eg.metals like your screwdriver is made of) when a magnetic field is induced into that object,and this is called residual magnetism(a small amount of charges have been separated). Some materials(like ferrite) are very difficult to separate there charges,and when the induced magnetic field is removed,the charges remain neutral.But once separated(usually by a highly concentraited and powerful magnetic pulse),this charge separation is very stable. Neodymium magnets are very strong because the material allows for a very large charge separation.

Tinman,

The more conventional understanding states that magnetic materials already contain magnetized domains, but due to their random orientation, the net observable magnetization is near zero.

The domains within soft iron align quite easily to an external magnetic field.  Soft iron has very low pinning forces to keep those domains aligned once the field is removed, so the domains within the iron return to the lower energy random orientation.

Harder alloys or PM materials have higher pinning forces.  These pinning forces must be overcome during magnetization (domain alignment) requiring a higher applied field strength, but once the pinning forces are overcome, the domains tend to remain aligned.  Magnet materials such as AlNiCo, SmCo, NdFeB, and the newer FeN are selected to have, amongst other qualities, very high pinning forces.

As an aside, here is an interesting video:

https://www.youtube.com/watch?v=HzxTqQ40wSU

PW