A neutron diffraction and isotopic substitution measurement of the structure of liquid Cu2Se

The partial structure factors and pair distribution functions of liquid Cu 2 Se have been determined by neutron diffraction with isotopic substitution. The structure shows characteristics typical of those of an ionic 2:1 melt consisting of Cu + and Se 2- ions with the cations moving through a more ordered Se 2- sub-structure. A detailed comparison has been made with recent results obtained for liquid Ag 2 Se. The structure is similar although there is no evidence of the double peak structure in the cation-cation partial structure factor, S CuCu ( Q ), as has been found in S AgAg ( Q ) for liquid Ag 2 Se and, to a more limited extent, for liquid Ag 2 Te. There is also less order in the Se 2- sub-structure based on a comparison of S SeSe ( Q ) and the Bhatia-Thornton concentration-concentration structure factor, S CC ( Q ), for the two liquids.