Ferromagnetic, refers to the magnetic state of a material, with spontaneous magnetization phenomenon.
The most well-known materials in the iron, so famous. Some materials are magnetized after the external magnetic field, even if the external magnetic field disappears, still can maintain its magnetization state and have magnetism, namely the so-called spontaneous magnetization phenomenon.
All permanent magnets are ferromagnetic or ferrous. Basically the concept of ferromagnetic includes any substance that shows magnetism when there is no external magnetic field. This concept is still being used so far. But through a more profound understanding of the different magnetic materials and their magnetism, scholars have made a more precise definition of the concept. It is called ferromagnetic when all the magnetic ions in the cell of a substance point to its magnetic direction. If only a part of the ion's magnetic field points to its magnetic direction, it is called the ferrous ferromagnetic.
If the direction of the magnetic ions is precisely offset (although all the magnetic ions point to only two opposite directions) is called the anti-ferromagnetic. The magnetic phenomenon of matter has a critical temperature at which it will occur. For ferromagnetic and ferrous ferromagnetic materials, this temperature is called Curie temperature;
For the anti ferromagnetic material, this temperature is called the Neil Temperature.
Some people think that the attraction between magnets and ferromagnetic materials is the earliest understanding of magnetism.
What is the role of a magnet before deciding which one to choose?
The main function: moving objects, fixing objects or lifting objects.
The shape of the magnet needed: a round, circular, square, tile, or special shape.
The size of the magnet required: long, wide, high, diameter and tolerances, and so on.
The required magnet suction, the expected price and quantity, and so on. The compass was invented on the basis of the nature of the magnet.