High precision measurements of the temperature dependence of the sound velocity in selected liquid metals

Anomalous and normal dependence of the sound velocity in the liquid Bi–Sb system

“…The derivative of the sound velocity with respect to temperature (dlnc/dT) at the liquidus of the Bi-Sb system, as a function of composition is shown in Fig.5 based on the results of the present measurements and previous studies [12,19]. It is found to 6 shows the isothermal composition dependence of the sound velocity at selected temperatures based on the present work and the results of Ref.…”

“…It is found to 6 shows the isothermal composition dependence of the sound velocity at selected temperatures based on the present work and the results of Ref. [12]. At all temperatures, the sound velocity increases monotonously with composition as the fraction of antimony is increased.…”

“…Since the distance between the buffer rod and the crucible is not known accurately enough, we modified the pulse-echo technique [12] and measured the sound velocity by displacing the buffer rod by a known distance, ΔX (Fig.2). This displacement leads to a change of 2ΔX in the path of the wave and Δt in the time interval required for the wave to travel through the liquid, hence, the sound…”

“…However, there also exist anomalous liquid metals such as Si, Ge, Sb and Te [3,13] that exhibit non-monotonic temperature dependence of the sound velocity , which first rises to a maximum and then proceeds to decrease. Semi-normal liquids have monotonic, but variable, temperature dependence of the sound velocity, such as Bi [3,12]. Focusing on the pnictides, a progression can be observed down the column from the significant sound velocity anomaly in As where the maximum in the temperature dependence has not yet been determined [14], through anomalous (positive) temperature dependence in Sb with a maximum at approximately 850 0 C [12], to semi-normal (variable) temperature dependence in Bi [12].…”

Temperature-Induced Liquid-Liquid Transition in Metallic Melts: A Brief Review on the New Physical Phenomenon

“…For example, by high-resolution measurements of the density, the heat capacity and the static structure factor, scientists out of Israel, USA and France found that a temperature-driven liquid-liquid structural transformation takes place quite above liquidus of Bi [55]. Also, with high precision measurements, Greenberg et al investigated the sound velocity-temperature behaviors in pure liquid tin and the results showed that at approximately 500 °C and 850 °C the data deviates by three times the experimental error from the linear fit [56]. By neutron diffraction and small-angle neutron scattering, a collaborative study on molten Al-Si alloys were carried out by University of Rouen (France), Ames Laboratory and Oak Ridge National Laboratory, and the results unambiguously show that for the eutectic Al-Si melt, the microstructure changes with increasing temperature in a partly reversible way, while for the hypereutectic (Al-Si20at%) melt, the change is almost completely irreversible [57].…”