How to make ferromagnetic material permanent magnetization?
Rub the magnetic material several times with one end of the magnet in the same direction
With the relevant materials if it is ferrite if the temperature is not FeCrCo permanent magnet -50---+400 better you need the magnetic field then magnetizing and demagnetizing saturation magnetization can be
The external magnetic field can make the magnetic material permanent magnetization, and can be an electromagnet and a pulsed magnetic field.
