Sound velocity in the molten As-Te system

The velocity of sound in the molten As-Te has been measured as a function of temperature, which shows up to 60 at.% As a pronounced minimum like in pure liquid Te. In an As- rich alloy, only a high temperature branch of the whole nu(s)-T curve that the sound velocity decreases rapidly with lowering temperature was obtained, because solidification took place before a minimum could be observed. The results suggest that rapid structural changes occur with varying temperature over the whole composition and confirm the recent experiments indicating that liquid As undergoes rapid structural changes with raising temperature like in supercooled Te. An extrapolation predicts a minimum in the sound velocity in As to occur at 736+/-6 degrees C. The Peierls distortion mechanism and stability of structure of the liquid sp-bonded elements are discussed.