Initializing process on direct overwrite method using exchange-coupled quadilayer 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. >
Progress in Magnetooptical Data Storage
Magnetic recording is widely used in many present applications, for instance, in tapes for audio and video recording or in floppy and hard disks for data storage [1–5]. Optical recording, on the other hand, is still an emerging technique [5,6]. In a consumer product it has started with the Compact audio disk and is now developing in many varieties, for instance, Compact Disk-Read Only Memories (CD-ROMs), Write-Once-Read-Many media (WORMs) or magnetooptical minidisks. For comparison of magnetic and optical recording the basic principles and the physical limitations of both techniques will be discussed in the following.
Amorphous materials for micrometer and submicrometer bubble domain technology
A review and critique is made of those material and processing issues that pertain to the implementation of micrometer and submicrometer bubble devices on amorphous films. Adequate reproducibility and uniformity have been achieved in ternary amorphous films prepared by rf sputtering and their magnetic characteristics are very similar to those of analogous garnet films. Factors that may limit application to the amorphous films include defects and dielectric breakdown in insulating layers, sensitivity to annealing, and larger, but not prohibitive, coercivities. A salient problem common to both garnet and amorphous materials is attainment of sufficiently large values of Q to ensure stable device operation.