Electric field effect on the Néel temperature of cobalt oxide formed at an alumina nano-oxide layer

The electric control of surface magnetism is important for spintronic applications. Due to the screening of electric field by conduction electrons in metals, an electric field can be applied only at a surface layer. However, the electric field can be applied on metallic contacts smaller than the electron's mean free path. We report on the electric modulation of the phase-transition temperature of CoO that is present at Co/Pt nano-contacts through a thin AlOx barrier. We found a 50-K/V change that can be attributed to the injection of electrons through nano-contacts.