Study on high reliability TbFeCoNb magneto-optical recording disk

Abstract
We studied the magnetic properties, corrosion resistance, and disk properties, using TbFeCoNb film for magneto‐optical film. Adding 2–3 at. % Nb to TbFeCo, the magnetic properties did not change, and the recorded domain on the disk using TbFeCoNb film is the same as on a TbFeCo film. TbFeCoNb film has high corrosion resistance for wet corrosion and pitting corrosion. The dependency of corrosion on the forming process is studied. The magnetic properties are dependent on the process such as rotational process and pass‐by process, but the corrosion resistance is independent. As a result, we have a high reliability and high‐performance magneto‐optical disk. Write/erase repetition cycles are more than 107. After this disk was held in 60 °C−90% RH (relative humidity) for 2000 h, carrier‐to‐noise ratio (C/N), and defect error rate had not changed.