• Michler, J.
• Coduri, M.
• Saksl, K.
• Milkovič, O.
• Putz, B.
• Edwards, T. E. J.
• Ipach, R.
• Pethö, L.
• Milkovičová, J.
• Mohanty, Gaurav
• Maeder, X.
• Schweizer, P.

Abstract

We report for the first-time combinatorial synthesis of thin film metallic glass libraries via magnetron co-sputtering at the limit of crystallinity. Special care was taken to prepare extremely pure CuZr films (1–2 µm thickness) with large compositional gradients (Cu18.2Zr81.8 to Cu74.8Zr25.2) on X-ray transparent polymer substrates in high-vacuum conditions. Combined mapping of atomic structure (synchrotron radiation) and chemical composition (X-ray fluorescence spectroscopy) revealed that over the entire composition range, covering multiple renowned glass formers, two phases are present in the film. Our high-resolution Synchrotron approach identified the two phases as: untextured amorphous Cu51Zr14 (cluster size 1.3 nm) and textured, nanocrystalline α-Zr (grain size 1–5 nm). Real space HR-STEM analyses of a representative composition substantiate our XRD results. Determined cluster and grain sizes are below the resolution limit of conventional laboratory-scale X-ray diffractometers. The presented phase mixture is not permitted in the Cu-Zr phase diagram and contrary to existing literature. The phase ratio follows a linear trend with amorphous films on the Cu-rich side and increasing amounts of α-Zr with increasing Zr content. While cluster size and composition of the amorphous phase remain constant thorough the compositional gradient, crystallite size and texture of the nanocrystalline α-Zr change as a function of Zr content. ; Peer reviewed

Topics

• impedance spectroscopy
• cluster
• polymer
• amorphous
• grain
• grain size
• phase
• x-ray diffraction
• thin film
• glass
• glass
• chemical composition
• transmission electron microscopy
• texture
• phase diagram
• crystallinity
• fluorescence spectroscopy
• X-ray fluorescence spectroscopy