Amorphous rare earth oxides

Claim 1

A magneto-optical recording medium, comprising a magneto-optical layer, end a dielectric layer comprising at least 51% by volume rare earth oxide and 2 to 49% by volume of a stabilizer for providing resistance to thermally induced crystallization of said dielectric layer, wherein said dielectric layer, when examined by transmission electron microscopy, exhibits a diffuse halo electron diffraction pattern and contains substantially no crystallites larger than 2 nm, thereby indicating said dielectric layer is amorphous, and wherein a film of said dielectric layer having a thickness of ≈100 nm deposited on a TbFeCo film having a thickness of ≈5 nm, after annealing at 300° C. for one hour in air, a 10 degrees≦2θ≦60 degrees X-ray diffraction scan using copper K-alpha incident radiation of said film of said dielectric layer on said TbFeCo film exhibits no X-ray diffraction peaks corresponding to a crystalline phase of composition, thereby indicating said dielectric layer is stable.