X-ray diffraction study of undercooled molten silicon

The short-range order of molten silicon was investigated in a wide temperat ure range from 1893 K down to 1403 K, corresponding to an undercooling of 2 90 K. Energy-dispersive x-ray diffraction was used in combination with elec tromagnetic levitation. The structure factor and the pair correlation funct ion were determined as a function of temperature from the experimental data . A small hump on the higher wave vector side of the first peak in the stru cture factor was observed at all temperatures. The position of the first pe ak in the pair distribution function shifted to shorter distances and its h eight increased gradually with decreasing temperature. No discontinuous beh avior was observed in the entire temperature range investigated. (C) 2001 A merican Institute of Physics.