Origin and application of magnetic materials
A magnet is not invented by man. It has natural magnetite. The first one to discover and use a magnet should be chinese. So compass is one of the four great inventions of the Chinese people. As for the component that is iron, cobalt and nickel. The special structure of the atom, atom itself has a magnetic moment. The mineral molecules in general confusion. Magnetic field will not affect each other. But in the magnetic force (e.g. magnetic field) under the guidance of molecular orientation consistency. On the show. Also known as magnetic magnet. Iron cobalt and nickel are magnetic materials most commonly used basically divided magnet permanent magnet and soft permanent magnet is coupled with the strong magnetic and electronic spin magnetic material angular momentum into fixed direction is soft magnetic and current (also a method with magnetic current) to remove iron will slowly lose magnetism as for the most as early as the magnet who found the oldest record is China emperor Chi You war guide car so called one of the four great inventions of Chinese! China that know the situation in the magnet polarized first Century bc. In the Warring States period, had used a natural magnet, on a scale of copper, used in divination.
Use of magnetic materials:1. the motor now popular brushless DC motor rotor is a permanent magnet;2. transformers need to work with magnetic materials3. magnet buckles in daily life.There are many, I can not remember for a while.
Sources of magnetic materials:1. natural magnetite2. artificial alloy containing cobalt and iron3. now, synthetic iron cobalt alloys containing rare earth elements are very magnetic.
