Structural instability and the metal–non-metal transition in expanded fluid metals

Abstract

X-ray diffraction, small angle X-ray scattering and inelastic X-ray scattering measurements for fluid Hg in the wide density range up to the supercritical region have been carried out using synchrotron radiation at SPring-8. We obtained the static and dynamic structure factors as a function of temperature, pressure and density. Based on the results we found that there exist medium-range fluctuations accompanying the metal-non-metal transition in fluid Hg. The scale of the fluctuations was about 10 A in space and sub-picoseconds in time. We discuss the possibility that such structural instability induces the metal-non-metal transition in expanded fluid Hg.

Computer Simulation And Modeling The Metal To Insulating Transition Of Liquid Mercury Via Pair, Empirical And Many-Body Potentials

“…1. Firstly, The overall feature of this curve coincides with previous studies [13,15,36,37,38], that manifest there is an inhomogeneous expansion, due to the first peak position in g(r) that as nearest neighbor distance, mainly remains constant, while coordination number turn down. (molecular-like) emerges in the phase space [13], consequently, the phase transition (M-NM)…”

Universality of the Phonon–Roton Spectrum in Liquids and Superfluidity of 4He

“…As an illustration, we present the results of later experiments with liquid titanium [12] (Fig.2). Furthermore, a similar excitation spectrum takes place for mercury in the vicinity of the metal-nonmetal transition [13,14].…”

Experimental techniques of high-resolution inelastic X-ray scattering measurements for supercritical metallic fluids at high temperature and high pressure using synchrotron radiation at SPring-8

“…This behavior suggests a much shorter lifetime of the propagating mode in the M-NM transition and may be related to a large ultrasonic absorption observed in the M-NM transition region [19]. However, the current-current correlation function deduced from the optimized model function exhibits a broad maximum around the excitation energy of the DHO component [20] and we could identify it as a function of Q. Figure 5 (c) shows E − Q dispersion in the M-NM transition.…”