Magnetism
The stand features three examples of magnetism, including experiments with iron filings, a floating spanner and repelling magnets. Today, the industrial importance of magnetic materials is huge. Magnets are used in wind turbines and gas-fuelled refrigerators, among other things.
Three experiments on magnetis
Magnetic field
In this experiment you can use a magnet to move the iron filings behind the plexiglass sheet. Iron filings are small, tiny pieces of iron that are affected by the magnetic field around the magnet. Usually the magnetic field is not visible, but using the iron filings we can see how the iron filings align with the magnetic field lines. Can you see where the magnetic field lines begin or end? How would you describe what the magnetic field looks like?
Floating wrench
It seems almost magical that the wrench can float. There is a strong permanent magnet at one end. The wrench is affected by the magnetic field from the magnet. The magnet attracts the wrench to itself. The attraction between the wrench and the magnet can be stronger than gravity and therefore causes the wrench to float in the air.
Repelling magnets
Can you push the magnets together? Can you feel the strong force of the magnets? A magnet always has two different ends or poles: the south pole and the north pole. Similar poles repel each other, they repel each other. Different poles are attracted to each other, they attract each other. This also happens between magnets. If you break a magnet in the centre, you get two new ones.
What is Uppsala University doing in this area?
Uppsala University has many years of experience in multidisciplinary research on magnetic materials where the functional properties of the materials are utilised in various applications. In our research we use quantum mechanical simulations for material design and advanced techniques for material synthesis and characterisation of the magnetic properties of materials. This includes the use of powerful neutron and X-ray sources in our research. Current focus areas are new permanent magnets built from environmentally friendly and abundant elements, and magnetic materials that can be used for magnetic cooling. Another research area is spintronics where the magnetic moment of the electron is utilised to achieve more than ordinary electronics, for example to build magnetic memories that complement today's semiconductor memories.
How is this used in society?
The industrial importance of magnetic materials is enormous; after semiconductor technology, magnetic materials are the largest industrial sector in the world. Examples of new magnetic materials include permanent magnets that can be used for renewable energy conversion in wind turbines and materials that can be used to develop magnetic refrigeration technologies that consume less energy than today's gas-liquid fridges. Today's society also generates huge amounts of digital data. With an ever-increasing need for energy, the information and communication technology sector is expected to become one of the most important sectors in the near future.