Antiferromagnetic (AF) NiO buffer layers used to exchange bias ferromagnetic layers and for domain stabilization in magnetoresistive sensors are primarily fabricated using a reactive sputtering technique developed by [1, 2] . Laser ablation [3] reactive MBE [4] and MOCVD [5] have also been employed for this purpose with some success. We have developed a new simpler process for depositing NiO films using ion beam sputtering. The technique involves the direct sputtering of a NiO target and so does not require an oxygen partial pressure.
The ion beam deposition chamber used to deposit the magnetic films has been described elsewhere [6] . A NiO target is sputtered by a neutralized Ar ion beam and the ejected material accumulates on substrates suspended 25 cm above the target. The deposition rate is 0.1Å/sec. The substrate temperature is approximately 60°C during deposition unless otherwise noted. An uniaxial anisotropy is established in the NiFe layers with permanent magnets which produce a 300 Oe uniform bias field, Hb, at the substrates during deposition. We use high-angle x-ray diffraction (XRD) to study the morphology of the NiO layers and low angle XRD to calibrate the film thickness. A vibrating-sample magnetometer equipped with a high temperature oven is used to determine the magnetic properties of the NiO/NiFe coupled films. Rutherford backscattering measurements show that the NiO is stoichiometric to within 1%.