Temperature Dependence of the Dynamic Structure Factor for SupercooledSn1−xPbxAlloys: A Test of Instability Theories for the Liquid-Solid Phase Transition

Abstract

Measurements of the dynamic structure factor at $Q_0$, the momentum transfer of the first maximum of $S(Q,0\mathrm{})\mathrm{}$, have been made for droplet samples of Sn and Sn + Pb liquid alloys into the supercooled region. It is shown that half-width variations with temperature are inconsistent with expectations from instability theories for the liquid-solid phase transition, but correlate well with changes in atomic diffusivities with alloy composition.