Question. Why are ferromagnetic elements/materials attracted to magnets? What about their chemistry causes the force to occur? I read in a few places it has to do with the electron pairs in the outer shell needing to be shared, but I don't know if I even believe in traditional atomic theory any more. Besides, there are several elements on the periodic table of the elements that should fit that bill but aren't ferromagnetic. Some are "paramagnetic" such as osmium (which is a really interesting element in its own right) and are partially permeable by flux and are therefore magnetic. Other sources say everything is magnetic to at least some degree. Any insight?
As a side note, upon researching methods of focusing magnetic flux and the characteristics of Cobalt, the expensive, softer precursor to neo magnets, I found that Cobalt has the highest flux saturation density of any known element. It wasn't until alloys were created that cobalt got shelved as the rare earth magnet of choice.
Interestingly, there's a characteristic of ferromagnetic materials known as magnetostriction in which durring exposure to a magnetizing field the shape and dimensions of the domains within the metal are consticted as they rotate.
This in turn creates heat, as a byproduct of friction, proportional to the material's susceptibility to magnetostriction.
Here's where it gets interesting. If cobalt exhibits 60 microstrains (on whatever arbitrary scale is used to describe this largely misunderstood phenomenon), then there is this alloy of Terbium, called Terfenol-D, which is the most highly magnetostrictive material yet discovered by mankind, and exhibits 2000 microstrains, according to UCLA.
Maybe I am misunderstanding the properties of this material, but correct me if I am wrong. Magnetized Terfenol-D can convert magnetic energy into kinetic energy, or the reverse, by creating friction, and therefore heat, during the fractional change in length as the magnetization of the material increases from zero to the saturation value, or conversely by absorbing the like during demagnetization. So does this mean that a sample of Terfenil-D will spontaneously heat up when exposed to a magnetic feild?!
As a side note, upon researching methods of focusing magnetic flux and the characteristics of Cobalt, the expensive, softer precursor to neo magnets, I found that Cobalt has the highest flux saturation density of any known element. It wasn't until alloys were created that cobalt got shelved as the rare earth magnet of choice.
Interestingly, there's a characteristic of ferromagnetic materials known as magnetostriction in which durring exposure to a magnetizing field the shape and dimensions of the domains within the metal are consticted as they rotate.
This in turn creates heat, as a byproduct of friction, proportional to the material's susceptibility to magnetostriction.
Here's where it gets interesting. If cobalt exhibits 60 microstrains (on whatever arbitrary scale is used to describe this largely misunderstood phenomenon), then there is this alloy of Terbium, called Terfenol-D, which is the most highly magnetostrictive material yet discovered by mankind, and exhibits 2000 microstrains, according to UCLA.
Maybe I am misunderstanding the properties of this material, but correct me if I am wrong. Magnetized Terfenol-D can convert magnetic energy into kinetic energy, or the reverse, by creating friction, and therefore heat, during the fractional change in length as the magnetization of the material increases from zero to the saturation value, or conversely by absorbing the like during demagnetization. So does this mean that a sample of Terfenil-D will spontaneously heat up when exposed to a magnetic feild?!