Material characteristics in magnetic field vary greatly

　　According to the molecular current hypothesis, the material in the field should exhibit similar characteristics, but here tells us that material characteristics in magnetic field vary greatly. This reflects the limitations of molecular current hypothesis.

　　In fact, all kinds of material microstructure is different, this kind of material structure difference is the difference of magnetic material.

　　We call the paramagnetic material and diamagnetic substance as weak magnetic material, and the ferromagnetic substance known as strong magnetic material. The magnetic material， commonly referred to is ferromagnetic material. According to the difficulty level of magnetization demagnetization, magnetic materials can be divided into soft magnetic materials and magnetic materials. After the magnetization, the substance that is easy to remove magnetic, is called soft magnetic materials, the substance, not easy to touch, is called hard magnetic material. Generally speaking, the remanence of soft magnetic material (permanent magnets) is little, and the residual magnetism of hard magnetic material is larger,