Structure of levitated Si–Ge melts studied by high-energy x-ray diffraction in combination with reverse Monte Carlo simulations

The short-range order in liquid Si, Ge and binary Six-Ge1-xalloys (x= 0.25, 0.50, 0.75) was studied by x-ray diffraction reverse Monte Carlo simulations. Experiments were performed the normal supercooled states using containerless technique of aerodynamic levitation with CO2laser heating, enabling deeper supercooling Si Si-Ge alloys than previously reported. local atomic structure resembles theβ-tin structure. first coordination numbers about 6 for all compositions are found to be independent temperature indicating liquids retain this high-density (HDL) However, there is evidence developing tetrahedral ordering, as manifested a shoulder on right side peak inS(Q) which becomes more prominent increasing supercooling. This result potentially indicative continuous transition from stable HDLβ-tin (high pressure) phase, towards metastable low-density reminiscent diamond (ambient