Thermal stability of ME recording media by measuring time and temperature effects

Different metal evaporated (ME) media were compared to investigate the cause of the temperature dependence of coercivity for ME media. It was found that exchange coupling and the temperature dependence of coercivity near room temperature are separate issues. By measuring the time dependence of coercivity, the crystalline anisotropy of Co was found to be the main cause of ME media's temperature dependence of coercivity. The switching volume for Hi8 ME medium was found to be extremely small, about 1100 nm/sup 3/, which indicates highly desirable low recording noise. Furthermore, by evaluating the value of K/sub u/V/K/sub B/T, ME media were found to be thermally stable.