EXCHANGE COUPLING BETWEEN NIO AND NIFE THIN-FILMS

NiO/NiFe bilayer thin films were prepared by rf reactive and dc magnet ron sputtering, respectively. The exchange coupling strength between N iO and NiFe as a function of NiO texture and interface roughness was i nvestigated by using different sputtering pressures, Au, and Cu buffer layers. The experimental results show that the exchange coupling fiel d strongly depends on the NiO/NiFe interface roughness. In addition, w e found the exchange coupling is largest for the (200) texture compare d to the (111)-texture films. This is surprising since the bulk spin s tructure of NiO predicts the (200) plane to be compensated-while the ( 111) plane is to be uncompensated. (C) 1996 American Institute of Phys ics.