Abstract
Influences of substrate materials and oxygen content in an annealing atmosphere on the corrosion resistance of Al-doped Fe-Ta-C magnetic thin films were studied by electrochemical methods. The reaction speed of pitting corrosion of Al doped Fe-Ta-C magnetic thin films prepared on a single crystalline Mn-Zn ferrite substrate was faster than that of the film prepared on a glass substrate. The high corrosion rate was associated with degradiation of the Fe (110) orientation, when the magnetic thin film was prepared on the ferrite substrate. When the Al-doped Fe-Ta-C films were annealed in an atmosphere containing oxygen, the pitting potential shifted to less noble potentials. The corrosion mechanism was studied by AES and ESCA. When the Al-doped Fe-Ta-C magnetic thin films were exposed to oxygen in the annealing atmosphere, Al in the alloys was preferentially oxidized and its concentration was reduced. As a result, the magnetic film became weak against pitting corrosion.
