March 2012

Researchers from the Helmholtz Center in Berlin developed a new magnetic valve that can be used for data storage or information processing. The new structure allows an indefinite number of re-write cycles.

The researchers created a defined anisotropy with two thin, stacked ferromagnetic layers: they wanted to create a structure in which a magnetic characteristic within the material changes in a well defined way. They added a third non-magnetic layer (made of Tantalum) between the two layers, which made the whole structure behave like a spin valve.

Researchers at the Max Planck Institute of Microstructure Physics in Halle developed a new switching mechanism for magnetic current. The idea is to use a short electric pulse to change the magnetic transport properties of a material sandwich consisting of a ferroelectric layer between two ferromagnetic materials. The new mechanism could be used to store information in four states of a storage point, not just two - which doubles storage density or lowers the size of MRAM devices.

In ferroelectric materials, voltage switches between the two directions of an electric polarisation – depending on its polarity – not unlike when a magnetic field permanently reverses the polarity of a ferromagnet. As ions shift within the material structure during this process, the polarisation remains intact, even after the voltage has been reduced. It is possible, however, to reverse the switch again with a similarly large voltage with reversed polarity.