Physical and chemical properties of nanostructured CoO–AlOx granular films Original Research Article

A series of nano CoO–AlOx granular films were prepared by Ar–O2 reactive rf sputtering and their resistive and magnetoresistive properties were measured for studying the spin-dependent properties. Transmission electron microscopy and X-ray photoelectron spectroscopy are also utilized to investigate the structures and chemical states of these samples. Based on our results, the particles of CoO with radius around 2 nm could be magnetic at room temperature and provide a large tunneling magnetoreststance of −6% through the AlOx barrier.