Exchange coupling of NiO/CoFeB films

Abstract The exchange coupling in NiO/CoFeB films was investigated. A unidirectional anisotropy was obtained in films with NiO layer thickness of 30–50 nm. The crystal texture of films and magnetic properties were found to be different when the stacking sequence was reversed. In glass/Cu/CoFeB/NiO films, a strong NiO (1 1 1) peak was observed with increasing NiO thickness and the exchange coupling field was about 30 Oe. On the other hand, in the reversed glass/NiO/CoFeB/Cu films, the intensity of the NiO (1 1 1) peak was much weaker and the exchange coupling field was about 60 Oe. A drastic increase in the coercivity was also observed.