Materials that can react to magnetic fields in some way are called magnetic materials. According to the magnetic strength of substances in the external magnetic field, they can be divided into diamagnetic substances, paramagnetic substances, ferromagnetic substances, antiferromagnetic substances and ferromagnetic substances. Most materials are diamagnetic or paramagnetic, and their response to external magnetic field is weak. Ferromagnetic materials and ferromagnetic materials are ferromagnetic materials. Generally speaking, magnetic materials refer to ferromagnetic materials. For magnetic materials, magnetization curve and hysteresis loop are characteristic curves reflecting their basic magnetic properties.
Ferromagnetic materials are generally Fe, Co, Ni elements and their alloys, rare earth elements and their alloys, and some Mn compounds. According to the difficulty of magnetization, magnetic materials are generally divided into soft magnetic materials and hard magnetic materials.
Experiments show that any substance can be more or less magnetized in an external magnetic field, but the degree of magnetization is different. According to the characteristics of substances in the external magnetic field, substances can be divided into five categories: paramagnetic substances, diamagnetic substances, ferromagnetic substances, ferromagnetic substances and diamagnetic substances.
Application of magnetic materials -- transformer
According to the molecular current hypothesis, matter should show roughly similar characteristics in the magnetic field, but it tells us that the characteristics of matter in the external magnetic field are very different. This reflects the limitations of the molecular current hypothesis. In fact, the microstructure of various substances is different, and the difference of material structure is the reason for the difference of material magnetism.
We call paramagnetic and diamagnetic substances weak magnetic substances and ferromagnetic substances strong magnetic substances.
Generally speaking, magnetic materials refer to strong magnetic materials. According to the difficulty of demagnetization after magnetization, magnetic materials can be divided into soft magnetic materials and hard magnetic materials. After magnetization, the material that is easy to remove magnetism is called soft magnetic material, and the material that is not easy to demagnetize is called hard magnetic material. Generally speaking, the remanence of soft magnetic materials is small and that of hard magnetic materials is large.
