Initializing process on direct overwrite method using exchange-coupled quadri-layered magneto-optical film

A direct overwrite mechanism of the exchange-coupled quadri-layered film using light intensity modulation has been investigation. The initializing process in the overwrite mechanism was studied. It was found that the writing layer had two different coercivities depending on the magnetization state of its adjacent layers. The coercivity of the writing layer in the initializing process was lower than that of the single layer. Thus, the overwrite recording was achieved with good recording characteristics. How this phenomenon plays a critical role in the initializing process was clarified. It was also found that this process occurred well above room temperature