Materials for spintronic: Room temperature ferromagnetism in Zn–Mn–O interfaces

Abstract In this paper we study the room temperature ferromagnetism reported on Mn-doped ZnO and ascribed to spin polarization of conduction electrons. We experimentally show that the ferromagnetic behaviour is associated to the coexistence of Mn 3+ and Mn +4 in MnO 2 grains where diffusion of Zn promotes the Mn 4+ →Mn 3+ reduction. Potential uses of this material in spintronic devices are analysed.