Amorphous GdCo disk for thermomagnetic recording

Abstract

Thermomagnetic recording was carried out on 150-mm-diam amorphous GdCo disks rotated at a speed of 1800 rpm. GdCo films showing good uniformity were deposited on glass disks by rf sputtering technique. Bits as small as 1 μm in width were recorded, making use of compensation temperature with a laser power of 5.6 mW and were read out with a laser power of about 2 mW. Thermal stability and dependence of the Kerr rotation angle on wavelength were also measured. It was confirmed that GdCo film is a most promising material for thermomagnetic recording.