Atomic structure and formation of CuZrAl bulk metallic glasses and composites

Graphical abstract: Partial radial distribution functions for Cu_47.5Zr_47.5Al₅ metallic glass and relevant crystal structures. - Abstract: Cu_47.5Zr_47.5Al₅ metallic glass is studied experimentally by high-energy X-ray diffraction, neutron diffraction with isotopic substitution, electron diffraction and X-ray absorption spectroscopy. The atomic structure of the glass is modeled by reverse Monte-Carlo and molecular dynamics simulations. RMC modeling of seven experimental datasets enabled reliable separation of all partial pair distribution functions for Cu_47.5Zr_47.5Al₅ metallic glass. A peculiar structural feature of the ternary alloy is formation of the strong Al–Zr bonds, which are supposed to determine its high viscosity and enhanced bulk glass formation. Analysis of the local atomic order in Cu_47.5Zr_47.5Al₅ glass and Cu₁₀Zr₇, CuZr₂ and CuZr B2 crystalline structures elucidates their similarities and differences explaining the phase formation sequence by devitrification of the glass.