Explanation

In a broad sense, it refers to the properties of materials that can form permanent magnets or can be attracted by magnets. The materials showing ferromagnetism are mainly iron, nickel, cobalt and a large part of alloy containing these elements. Some compounds containing rare earth elements and some naturally formed minerals, such as natural magnets, also have ferromagnetism. The magnetism of materials results from the ordered arrangement of ion magnetic moment. ferromagnetism materials means that all the magnetic moment of ions in it are arranged in the same direction? Thus, the contribution of each ion magnetic moment to the materials's macro magnetism is positive. The magnetism of matter is a quantum mechanical phenomenon, which is essentially due to the spin behavior of electrons in the constituent elements of matter and the Pauli exclusion principle that electrons must follow. Due to spin motion, each electron carries a magnetic dipole moment, which behaves like a tiny magnet. The spin direction of electrons can be divided into two types: "up" and "down". When the electrons with opposite spin directions are paired together, their magnetic dipole moments cancel each other and their contributions to the macro magnetism of materials are zero. When there are a large number of unpaired electrons with the same spin in the materials, the magnetic field of the magnetic dipole moments of these electrons are mutually superposed and strengthened, so that the materials shows the magnetic properties that can be measured macroscopically. Therefore, ferromagnetism can only be produced in some materials containing partially filled electron shell elements. In recent years, periodic long-range magnetic interactions caused by the regular arrangement of electron spins in some doped semiconductor semiconductor oxide materials have been found, These advanced materials are called spin electronic materials. The magnetism of materials is a function of the ambient temperature. When the temperature rises to the extent that the aligned spin electron arrangement in materials is destroyed, second-order transformation will occur in materials to make their magnetism disappear. This critical temperature is called Curie temperature 0

Classification