Toward cluster-assembled metallic glasses

Amorphous CuZr metallic films were fabricated by deposition of gas phase metal clusters on commercially available amorphous borosilicate glass substrates under ultra-high vacuum and soft-landing conditions. The cluster beam technology was employed for the first time to validate the feasibility of its use as a production approach for glassy materials. The mixed metal clusters were generated by a state-of-the-art high frequency pulsed laser vaporization cluster beam source from an alloy target. The structure of the films was studied by surface X-ray diffraction at the European Synchrotron Radiation Facility. The recorded X-ray diffraction patterns reveal that the cluster-assembled films lack crystalline structure. A halo peak corresponding to a scattering vector of 27.4 nm(-1) is observed in the created cluster-assembled material, which confirms the glassy structure of the film. After annealing the sample at 450 K for 10 minutes two crystalline structures emerge, namely the pure copper and the intermetallic CuZr phases. These two crystalline phases are also observed for as prepared (without annealing) cluster-assembled films with a thickness of about 600 nm.