Fabrication And Characterization Of Al-based Metallic Glass Thin Films

Since metallic glasses have been invented, the materials have attracted increasing interests due to their unique physic, chemical and mechanical properties. Compared to the crystalline alloy materials, metallic glasses are amorphous and exhibit some special feathers, such as homogeneous and isotropy, no lattice defects and no size effect. In the Al-Ni-Gd metallic glass system, the composition of Al element is more than 80at% and this system has good glass forming ability. Nowadays, the research has been focused on how to make bulk metallic glass materials, but the preparation and properties research of metallic glass thin films are rarely reported.In this paper, Al-based metallic glass thin films are further studied. Firstly, we find a suitable composition system in the existing various systems of Al-based metallic glass alloy compositions, which is Al-Ni-Gd ternary alloy system. Amorphous Al-based metallic glass thin films are obtained by magnetron sputtering method and annealing process is applied to prepare crystalline Al-based metallic glass thin films. The crystal structure, surface morphology, thermal, optical and electrical properties are well studied. We find that the crystallization rate of Al-based metallic glass thin films has a negative correlation with Ar pressure, and the thin films show a strong dependence of optical properties on its crystal structure. The reflectivity of amorphous Al-based metallic glass thin films is much higher than that of crystalline thin films. At last, the Al-based metallic glass thin films show little resistivity difference between amorphous state and crystalline state.