Self flipping magnets could improve MRAM architecture

Researchers at Johannes Gutenberg University Mainz (JGU) are looking to exploit a novel effect arising from the relativistic physics of Einstein in which magnets can flip themselves through the internal motion of their electrons. The team compares this to the ability of a cat to flip itself in the air by twisting different parts of its body in different directions and land on its feet.

In particular, the work is focused on a Heusler alloy of nickel, manganese and antimony (NiMnSb). “In these new magnetic materials,” said Professor Jairo Sinova, “a current running through the magnet can change the direction of magnetisation, depending on the direction of the current.” This phenomenon is dubbed spin-orbit torques.

Researchers first observed spin-orbit torques in the artificial bulk diluted magnetic semiconductor GaMnAs. However, these spin-orbit torques were only seen at very low temperatures.

Working with scientists from Prague, Cambridge, Würzburg, Jülich, and Nottingham, Prof Sinova and his team have predicted and demonstrated the effect of spin-orbit torques in NiMnSb crystals at room temperature.

The ability to use single magnet manipulation at room temperature is said to represent an important step towards improved MRAM architectures.