Read/Write Characteristics of Sputtered Garnet Optical Disks

The read/write characteristics of sputtered garnet magneto-optical disks are described. Polycrystaline films are grown on a glass substrate. In majority of the noise was found to come from the grain boundary. A good film was obtained under optimal sputtering conditions, with a carrier to noise ratio (CNR) of 45 dB. On a GGG substrate, an epitaxial film was obtained. Its CNR was 52 dB. No great improvement over a glass substrate was obtained. It seems that crystal defects are the cause of the noise.