Ultimate Fridge Magnets Could Save Energy

Magnetic refrigeration technology could use 20-30 percent less energy than traditional gas-compression fridges and air conditioners used today. But the material needed to make them work hasn't been determined.

Now a step has been made toward figuring out what materials will work best.

A magnetic refrigeration system works by applying a magnetic field to a magnetic material — some of the most promising being metallic alloys — causing it to heat up. This excess heat is removed from the system by water, cooling the material back down to its original temperature. When the magnetic field is removed the material cools down even further, and it is this cooling property that researchers hope to harness for a wide variety of cooling applications.

Engineers need a material that exhibits dramatic heating and cooling when a magnetic field is applied and removed, which can operate in normal everyday conditions, and which does not lose efficiency when the cooling cycle is repeated time after time.

A new study shows that microstructure pattern of crystals inside different alloys has a direct effect on how well they could perform at the heart of a magnetic fridge. Imperial College London say this finding could, in the future, help them to custom-design the best material for the job.

The findings were published today in the journal Advanced Materials.