Magnetic activation volumes of obliquely evaporated Co–CoO tape

Magnetic activation volumes of obliquely evaporated Co–CoO tape were investigated. With introduction of oxygen, magnetic activation volume calculated from irreversible susceptibility and magnetic viscosity coefficient was saturated to almost 6.0×10−24 m3, which is due to the columnar structure caused from the oblique evaporation. Using this measurement, the carrier to noise ratio of Co–CoO tape can be estimated quantitatively.