From a spin angle, what material has magnetism?
It is generally believed that a magnetic material is a substance that produces magnetism directly or indirectly by excessive elements such as iron, cobalt, nickel, and their alloys. Experiments show that any substance can be magnetized more or less in an external magnetic field, but only in varying degrees of magnetization. According to the characteristics of a substance in an external magnetic field, matter can be divided into five classes: paramagnetic, diamagnetic, ferromagnetic, sub magnetic, diamagnetic.
Magnetic material is an old and widely used functional material, and the magnetism of material has been recognized and applied as early as 3000 years ago. For example, in ancient China, natural magnets were used as the compass. Modern magnetic materials have been widely used in our daily life, such as the permanent magnetic material is used as the core material used in motor, transformer, magnetic disc memory used as magnetic recording by computer, such as floppy disks. It can be said that magnetic materials are closely related to information, automation, mechatronics, national defense and the national economy.
We call paramagnetic and diamagnetic substances weak magnetic substances and ferromagnetic substances called ferromagnetic substances. Generally referred to as magnetic material is a strong magnetic material. Magnetic materials are difficult to be divided into soft magnetic materials and hard magnetic materials after magnetization. It is easy to remove the magnetic material after magnetization. It is called soft magnetic material. The material which is not easy to touch is called hard magnetic material. Generally speaking, soft magnetic materials have residual magnetism
