This is because the raw material consists of many magnetic crystallites whose magnetic moments cancel each other until they are aligned. Of course a lump of iron is not normally a magnet, but has to be "magnetised" by some other magnet. When they point in the same direction on all the atoms, the material itself acts like a magnet it is called a ferromagnet, since the simplest example is BCC iron. In permanent magnets unpaired electrons spinning on atoms act as small electro-magnets pointing in particular directions i.e., they have a "north" and a "south" pole.
Metal detectors use this phenomenon to induce a magnetic field and measure its strength in the conductive material. Toby, Any electrically conductive material can be turned into an electromagnet by surrounding it in a flow of electrons (applying a current in an induction coil surrounding the conductive material). It's certainly not impossible, any more than superconductivity or lasers or compasses are impossible, but I don't know of current research on a theory that will lead to such a device.Ī.
As far as I know, here is no known magnet for gold with today's technology, and I haven't heard of theories being advanced that might lead to it any time soon. "Driving Force:The Natural Magic of Magnets"
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