Researchers at Tohoku University managed to find the origin and the mechanism of ferromagnetism in Mn-doped GaAs. This phenomonon has been puzzling researchers for over 20 years, and this new explanation may help to accelerate the development of spintronic devices made from such materials.
Mn-doped GaAs crystals exhibit characteristics and properties of both semiconductor and magnet. It is possible to use an electric field to control the magnetism in such materials - which makes them very appealing candidates for spintronic devices.
The researchers now discovered that the doped Manganese atoms extract electrons from the Arsenic atoms - which leave electron "holes" int he As orbital which causes the ferromagnetism.