Paramagnetic substance

As the name suggests, this material will adapt to changes in the magnetic field, which means that the additional magnetic field is in the same direction as the external magnetic field, causing the magnetic field B '' in the magnetized medium to be greater than the original magnetic field B '', but the difference in magnitude between the two is very small, which means that the relative magnetic permeability μ It is a constant slightly larger than 1. Aluminum, chromium, manganese, nitrogen, and air are all paramagnetic substances.

Diamagnetic substance

Contrary to paramagnetic substances, diamagnetic substances resist changes in magnetic fields, meaning that the additional magnetic field after magnetization is reversed from the external magnetic field. The magnetic field B '' in the medium after magnetization is smaller than the original magnetic field B, and the difference in magnitude between the two is also very small, μ It is a constant slightly smaller than 1. Bismuth, copper, silver, hydrogen, etc. are diamagnetic substances.

Ferromagnetic material

This is amazing. After magnetization, the additional magnetic field is also in the same direction as the external magnetic field, but the difference is that it can increase the magnetized magnetic field by thousands or even tens of thousands of times. That is to say, the relative magnetic permeability of this substance μ Far greater than 1, and this μ It is not yet a constant, it is related to the original magnetic field B (the upper two μ Both are constants.