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Magnetic and non-magnetic materials

The following materials can be magnetized and attracted by a magnet:

iron     steel     cobalt     nickel

Not all materials can be magnetized, the following are examples of the many materials that cannot:

Lead     aluminium     brass     copper     tin     wood     plastic     glass

The magnetic properties of iron and steel

Steel is used for making permanent magnets because although it is quite difficult to magnetise it, it is also difficult to demagnetise. Iron is used for making electromagnets that are switched on and off. It is easy to magnetise and demagnetise.

Other magnetic materials

Many new kinds of magnetic materials have been made since the discovery of lodestone. One of these is ferrite - a ceramic material made from magnetic powder (a mixture of iron oxide and barium oxide). Ferrites are used in radio aerials and you will probably have used one type - magnadur - in your school. These ceramic magnets are magnetsied when the material is soft and then fired to produced strong but rather brittle magnetic materials.

Other materials used are Alnico (a mixture of iron, nickel, cobalt and aluminium giving a permanent magnet) and Mumetal (nickel, iron and copper) giving a material that can be magnetised and demagnetised easily.

© Keith Gibbs 2020