Helmholtz-Zentrum Berlin für Materialien und Energie

They have demonstrated this phenomenon on thin layers of ferroelectric barium titanate covered with ferromagnetic iron or cobalt atoms. Using the HZB’s synchrotron radiation source BESSY II, researchers have observed that the interface between the two materials exhibit both ferroelectric and ferromagnetic behaviour. “When you apply an external voltage, it reverses the polarisation of the barium titanate film, which in turn influences its magnetisation,” says HZB researcher Dr. Sergio Valencia. This quality lends the material great potential as a storage medium. “Until now, information has been written on storage media by applying an external magnetic field, a process that requires a great deal of energy. If we can couple ferroelectric and ferromagnetic qualities strongly enough, it could be possible to influence magnetic orientation using an electric field and thereby save over 90 percent of the energy normally required,” explains Valencia. When these two properties are only weakly coupled, the storage medium that can be developed is based on four rather than two ground states.

HZB/Red.