Local order and phase separation in sulphur–tellurium melts: a neutron scattering study

Abstract

A neutron scattering investigation of the local order in liquid sulphur–tellurium was performed for alloys at xs=0.2, 0.3, 0.4, 0.6 and 0.8, at three temperatures. A detailed analysis of the structure in terms of partial coordination number is performed by means of a modelling of the structure factors at large momentum-transfer range. Local order changes are essentially caused by tellurium whose coordination number decrease from 2.6 to 1.8 in a 20% composition range. The change in the local atomic environment is shown to be responsible for the observed miscibility gap that occurs around xs=0.4.