magnet

A magnet is an object that forms a magnetic field. It has a north pole and a south pole. As iron is a magnetic material, iron filings shaken around a magnet will form along the lines of force and produce the pattern of the magnetic field.

Any object that possesses a magnetic field (displays magnetism), either permanently or temporarily through induction, causing it to attract materials such as iron, cobalt, nickel, and alloys of these. It always has two magnetic poles, called north and south. A device that generates a magnetic field by means of electric currents – often increased by a ‘core’ made of iron or other magnetic material – is called an electromagnet.

The most intense controlled magnetic fields are delivered by electromagnets energized by pulses of intense electric current. Europe's most powerful magnetic-field facility is at LNCMP (Laboratoire National des Champs Magnétiques Pulsés in Toulouse, France, which can generate fields over 60 teslas.

In the United States the NHMFL (National High Magnetic Field Laboratory) has a number of powerful machines at three major facilities, including the 100 Tesla Multi-shot Magnet at Los Alamos National Laboratory, which was commissioned in October 2006.

In 2004 scientists at the University of Durham in northeast England invented the first plastic magnet that could operate at room temperature. The new plastic magnetic material was made by combining tetracyanoquinodimethane (TCNQ) with emeraldine base polyalinine (PANi). The material became magnetic over time by the alignment of free radicals that mimics electron spin alignments in metal-based magnets.