High reliability magneto-optic media

Amorphous alloys of rare earths and transition metals used for magneto-optic (MO) recording are extremely reactive to oxygen and water resulting in severe oxidation and corrosion pitting of the media making it unrecordable. We have shown earlier [D. Majumdar and T. K. Hatwar, J. Vac. Sci. Technol. A 7, 2673 (1989)] that the addition of an easily oxidized element such as Zr is effective in suppressing pitting corrosion, while the addition of a noble element such as Pt is effective in retarding the surface oxidation of the film. We found that when both Zr and Pd were added to TbFeCo, the synergetic effect was such that better corrosion and oxidation resistances were obtained at lower concentrations of the alloying elements. This was accomplished with no decrease in carrier-to-noise ratio and a 30% decrease in optimum record power, relative to undoped TbFeCo.