Why does the earth's high-temperature liquefied iron core produce a huge magnetic field?
Large bar magnets lose their magnetism when being heated. The atoms in the magnet are arranged neatly according to a certain rule, which is the reason why the magnet is magnetic. When the magnet is heated, the arrangement of atoms is disrupted and the magnetism is reduced. When heated to 770°C, the magnet loses its magnetism.The temperature of the earth's core is so high that the iron core is in a liquid state, but it generates a strong magnetic field to protect the earth's life. The magnet loses its magnetism when heated, but the earth's core is hot but possesses a magnetic field. This seems contradictory.
At present, there are many theories to answer this question, and the generally accepted theory is the generator theory, that is, the core of the earth generates a continuous magnetic field like a generator. The core is composed of an inner core and an outer core. The outer core has a high temperature and is in a liquid state, but the inner core has a very high pressure and is in a solid state. Due to the rotation of the earth, the hot molten iron (which is a conductive material) in the outer core also flows. In this process, a current is generated due to magnetic induction, thereby generating a weak magnetic field. The electric current interacts with the fluid motion to increase the magnetic field, thereby generating a stronger and continuous magnetic field. Unless the fluid movement in the outer core stops, the earth's core will not stop generating magnetic fields.
In short, the high-temperature molten iron in the earth's core does not directly generate a magnetic field, but generates electric current through motion, which in turn produces electromagnetic effects, and finally produces a strong magnetic field in the earth's core.