X-ray diffraction study of molten eutectic LiF–NaF–KF mixture

The structure of molten eutectic LiF–NaF–KF (46.5; 11.5; 42.0 mol%) mixture at 520 °C has been investigated using the radial-distribution function based on X-ray scattered intensity data and analysed by the correlation method. The nearest-neighbour distances of unlike-ions, Li–F, Na–F and K–F, were 1.83, 2.18 and 2.59 Å, respectively, and their respective coordination numbers were 3.3, 3.8 and 4.0. These values are almost the same as those in the pure melts. The result indicates that in the ternary mixture the short-range structures of unlike ion pairs do not change on mixing nor in binary melts.