Chapter-5|Magnetism and Matter| NCERT 12th Physics:
Permanent Magnets:
The substances which at room temperature retain their ferromagnetic property for a long period of time are called permanent magnets. Permanent magnet can be made by placing a rod of ferromagnetic material in a current carrying solenoid. The magnetic field of the solenoid magnetises the rod.
The material used for making permanent magnets should have high retentivity, so that the magnet is strong and have high coercivity. steel is favoured for making permanent magnet. Some suitable materials for making permanent magnets are Alnico, Cobalt, steel and ticonal etc.