The Structure of Metal Evaporated Tape

To investigate the structure of evaporated tapes used in magnetic recording, and particularly the possible presence of a surface oxide layer, several tape samples were fabricated by oxygen reaction oblique-incidence evaporation, varying the amount of reacting oxygen, and analyzed the sample structures by XPS, AES, and X-ray diffraction. It was found that the region near the surface is a mixed phase of metal atoms and oxides. These oxides changed from CoO to Co3O4+CoO, and then to Co3O4, as the amount of oxygen was increased. However, intermixing of CoO with metal atoms is thought to contribute to the film durability.