Neutron diffraction study of liquid SixTe100-x (X ≤ 20) alloys

The structures of liquid SiXTe100-X alloys with 0 < X less than or equal to 20 have been investigated by neutron diffraction measurements. The structure factor, S(q), of liquid SiXTe100-X alloys with X = 10, 15 and 20 has a prepeak at around q = 1.0 Angstrom(-1) at lower temperatures, which suggests the existence of medium-range order in these liquids. The prepeak of S(q) for liquid Si10Te90 and Si15Te85 alloys disappears at higher temperatures, while that for liquid Si20Te80 remains. The coordination numbers of Si and Te are about 4 and 2, respectively. It seems that the tetrahedral configuration of SiTe4 in the Si2Te3 crystal may partly remain in the liquid state. (C) 2002 Elsevier Science B.V. All rights reserved.