Diffraction study of calcium aluminate glasses and melts: II. High energy x-ray diffraction on melts

High energy x-ray diffraction measurements have been performed on CaO-Al(2)O(3) liquids suspended in a flow of pure argon for six compositions containing 50-67 mol% CaO. The results indicate that AlO(4) tetrahedra dominate the liquid structure. The radial distribution functions show a significant broadening of the Ca-O peak occurs in the liquid compared to the corresponding glass and, on average, each Ca is surrounded by approximately five oxygen atoms in the melt at a distance of 2.3 angstrom. It is also found that the structure for the eutectic (64% CaO) liquid does not change measurably with temperature between 1600 and 1970 degrees C.