Thermophysical properties and atomic arrangement of liquid Zr_75−xNi₂₅Al_x glass-forming alloys investigated by electrostatic levitation experiments and molecular dynamics simulations

The thermophysical properties and atomic arrangement of liquid Zr_75−xNi₂₅Al_x (x = 8, 11, 15, 19, and 24) alloys were systematically investigated using an electrostatic levitation technique and molecular dynamics (MD) simulations. The density measurements revealed a distinct non-monotonic evolution in the relative density difference between liquid and crystalline solid states, where Zr₆₀Ni₂₅Al₁₅ exhibited a minimal difference of 0.16%, reflecting a high degree of liquid–solid structural similarity. Furthermore, the viscosity measurements confirmed that this composition possessed exceptionally sluggish dynamics for viscous flow, evidenced by the maxima in both viscosity (83.9 mPa s) and activation energy (102.9 kJ mol⁻¹) at the liquidus temperature. A correlation between the thermophysical properties and the atomic arrangement of Zr–Ni–Al alloys was elucidated by MD simulations, attributing the unique property extrema to both the strong Zr–Al bond formation and an optimal Al concentration that effectively suppresses Al–Al clustering.