Neutron diffraction of liquid Sn-Se system

The time-of-flight neutron scattering measurements have been carried out fo r liquid Sn-Se system. A distinct change in structural properties has been observed between Sn70Se30 and Sn60Se40, composition of which corresponds to that of maximum of the miscibility gap. The atomic configuration of liquid SnSe have been compared to that of molten NaCl. It is found that the bondi ng nature between Sn and Se in liquid SnSe is ionic rather than covalent. A small but apparent pre-peak at Q = 1.2 Angstrom(-1) in the structure facto r for liquid SnSe2 is found above the melting point. It suggests that the n etwork structure remains after melting. The intensity of this pre-peak decr eases with increasing temperature, indicating that the network structure is destroyed.