Magnetic materials:
Ferromagnetic materials can be easily magnetised and exhibit strong magnetic properties. This group can be further subdivided into hard and soft magnetic materials.
Above certain temperatures ferromagnetic materials behave as paramagnetic materials.
Hard Iron
Hard magnetic materials are more difficult to magnetise but retain most of their magnetism when the magnetising force is removed.
Examples steel and nickel alloys such as:
Ticonal Iron Cobalt / Nickel / Aluminium / Titanium and Copper
Alnico Iron Nickel / Cobalt And Aluminium
These materials are used for permanent magnets
Soft Iron
Soft magnetic materials become magnetised very easily, but they loose most of the magnetism when the magnetising force is removed.
Examples alloys such as stalloy and mumetal
These materials are used for temporary magnets
PARAMAGNETIC MATERIALS
Most materials fall into this group. These materials can only be magnetised with a great amount of effort, usually resulting in their destruction. If magnetised the material only exhibits small magnetic properties.
Examples - Wood / Glass /Air / Water / Aluminium
DIAMAGNETIC MATERIALS
This is a small group of materials that actually oppose a magnetising force. If placed in a magnetic field they will decreases its strength. If suspended in a magnetic field, they will swing to adopt a position at 90 degrees to the lines of flux.
Examples - Copper / Brass / Bronze / Mercury / Bismuth