Structural evolution and thermophysical properties of ZrxNi100 − x metallic liquids and glasses

• Structures of Zr–Ni liquid and glass alloys were measured.
• Density, thermal expansion coefficients, and viscosity were measured for all alloys.
• All alloys show an acceleration of structural ordering near the glass transition.
• Asymmetries in the first peaks in the pair distributions indicate chemical ordering.

The results of high-energy X-ray scattering studies over a wide temperature range for equilibrium and supercooled ZrxNi100 − x (x = 36, 57, 76) liquids and the corresponding glasses are presented. The results of liquid density and viscosity measurements are also shown. All of the liquid studies were made on containerlessly processed liquids using the technique of electrostatic levitation. The scattering data were used to determine the temperature-dependent total structure factor, S(q), and pair-correlation function, g(r). A discontinuity is observed between the magnitude of the first peak in S(q) of the liquid when extrapolated to the glass transition temperature, Tg, and the value determined for the structurally relaxed glass at Tg. This indicates that the structural ordering in the liquid accelerates upon approaching Tg, consistent with the behavior expected for a fragile liquid. An asymmetry in the first peak in the pair correlation function develops with decreasing temperature for all alloy liquids and glasses, suggesting that chemical ordering accompanies the structural ordering.