Short-range and medium-range order in molten Ga–Tl alloys

Molten alloys of Ga–Tl were investigated by neutron small- and wide-angle scattering around the miscibility gap which occurs in the liquid state of this binary system. For the alloy containing 40 at.% Tl (the critical composition) and these of 5 at.%Tl less and more than that of the critical composition, an increase of the small-angle scattering intensity was observed as the temperature is decreased and approaches the temperature at the binodal curve, whereas the wide-angle scattering data show no temperature-dependent behaviour in the considered temperature-range. The Ornstein–Zernike formalism was applied to the small-angle scattering data and values for the critical-point exponents ν and γ were estimated. The latter are in good agreement with theoretical values and with results published for other demixing systems.