People didn't invent the magnet, there is a natural magnetite, the earliest discovery and use of magnet should be Chinese.
So the compass is one of the four great inventions of the Chinese people.
As for the composition that is iron, cobalt, nickel, etc.
Special in its atomic structure, atomic itself has a magnetic moment.
Generally these mineral molecules arranged chaos.
Interact with each other just don't show the magnetic magnetic area.
But in the external force (
Such as magnetic field)
Guided by the molecular orientation of converged.
Just show magnetic.
Also known as the magnet.
Iron cobalt nickel is the most commonly used permanent magnets and magnetic materials basically magnet soft iron permanent magnet is strong magnetic combined to make the spin of magnetic materials and electronic angular momentum into fixed direction arrangement soft magnetic is combined with current (
Is also a kind of combined with magnetic method)
Such as current remove soft iron will slowly lose magnetism as for the first magnet who found the oldest recorded is the Chinese yellow emperor war human-god, so known as one of the four great inventions of China!
In the first century BC in China, namely, know a magnet polarization.
The warring states period, it has used a natural magnet, on a scale of copper plate, used for divination.
When the northern song dynasty used two methods to create artificial magnets, a red-hot iron needles, placed in the north and south direction, after rapid cooling, using the earth's magnetic field will be magnetized iron needles;
Another is to use a magnet friction iron needle.
The MengXi stature is recorded by the existence of the magnetic declination, found under the influence of the magnetic declination and magnetic needle points to the south, than the real south by east.
On the basis of these knowledge, and develop the application of the science of magnet as a compass.
Magnet is a general term, is refers to the things of magnetic, the actual component may not contain iron.
A pure metal state itself has no permanent magnetic iron, only close to the permanent magnets can produce magnetic induction, general permanent magnet inside added other impurity elements (
Such as carbon)
To make magnetic stabilized, but it will reduce the electronic freedom and less prone to conduct electricity, so the current through the bulb light up.
Iron is a common magnetic elements, but many other elements have a stronger magnetic, like many powerful magnets is the mixture of rubidium iron boron.