Recording Characteristics of Double-Layered Tbfeco Disk

Exchange-coupled double-layered TbFeCo films, consisting of a transition metal-dominant first layer and a rare earth-dominant second layer, were found to serve as high-performance media for erasable optical disks. In this paper, we describe studies of the dependence of the recording characteristics on the magnetic properties of each layer. The temperature dependence of the switching field for each layer as measured using the Hall effect is described, and the change in the magnetization process with temperature is discussed. It is suggested that the recording noise in the large-Hc1 (coercive force of the first layer) film at lower write powers results from differences in the magnetization process with the recording temperature.