What happens in a semiconductor as it becomes a magnet?
—First step to the next-generation spintronics—
Ferromagnetic semiconductors are functional materials pivotal to the development of spintronics, which are poised to be the next generation of information processing. However, in general, the Curie temperature, below which ferromagnetic ordering occurs, is much lower than room temperature. Understanding of the mechanism of ferromagnetism, which had not been unveiled since ferromagnetic semiconductors were discovered, was highly required for realizing room-temperature spintronics devices.
The research group established by the Japan Atomic Energy Agency, Tokyo University, Kyoto Sangyo University, and other organizations succeeded in elucidating the mechanism of ferromagnetism in manganese-doped gallium arsenide, a prototype of ferromagnetic semiconductors, using synchrotron radiation. They investigated how the conditions of the material affect their magnetic properties and ordering, and revealed the mechanism at the atomic level.
The insights about the onset of ferromagnetic ordering provide guideline on improvement in the performance and on new design concepts of ferromagnetic semiconductors, and will aid in the creation of practical, room-temperature spintronics devices.