Ultra-high-density phase-change storage using AlNiGd metallic glass thin film as recording layer

A nonchalcogenide inorganic blu-ray super-resolution near-field optical disk was successfully developed using an Al-based metallic glass as the recording layer. Data were recorded based on the large reflectivity change obtained during transformation from the amorphous state to the crystalline state upon laser irradiation. The optical and thermal properties of the Al90Ni3Gd7 metallic glass thin film were studied. The crystallization and melting temperatures were higher and more thermally stable than that of conventionally used Ge2Sb2Te5 chalcogenide phase-change recording material. Al90Ni3Gd7 metallic glass also demonstrated fast phase-change response to blue laser. Dynamic recording performance of this new structure showed good carrier-to-noise ratio and readout stability.