A team of scientists at Hokkaido University's Research Institute have reported on two forms of strontium cobalt oxide (SrCoO x): one is an insulating non-magnet while the other is a metal magnet. By changing the oxygen content through electrochemical oxidation/reduction the magnetic state of the material can be altered.
To do this the research team developed a method to use strontium cobalt oxide safely at room temperature in air without leaking an alkaline solution. This was done by applying a sodium tantalate thin film over layers of strontium cobalt oxide. When a three-volt current was applied the insulating form of SrCoO 2.5 reversibly switched to its metal magnet form, SrCoO 3, in three seconds.
Making the device smaller would shorten the time needed for the compound to switch between an insulator and a magnet, the researchers say.
Related links and articles:
Katase T. et. al., Reversibly switchable electromagnetic device with leakage-free electrolyte, Advanced Electronic Materials , Mar 29, 2016.