Cluster phase transitions and critical phenomena in fluid mercury

Fast Sound in Expanded Fluid Hg Accompanying the Metal-Nonmetal Transition

“…The amount of deviation is about 17%, in good agreement with previous work [17]. At 9:0 g cm ÿ3 , the positive deviation is much more pronounced and the effective velocity, v s Q Q =Q, is estimated to be 1500 200 m s ÿ1 , which is triple the ultrasonic sound velocity [7,8]. In the curve fitting with the DHO model shown in Fig.…”

“…We have now observed the excitation energy of the collective mode in expanded fluid Hg near the metal-nonmetal (M-NM) transition to be much higher than expected from low frequency measurements. The effective velocity deduced from the dispersion relation is 1500 m s ÿ1 while the ultrasonic sound velocity is 490 m s ÿ1 [7,8]. The present observation suggests the existence of fast sound in expanded fluid Hg accompanying the M-NM transition.…”

“…This behavior suggests a much shorter lifetime of phonons at the M-NM transition and may be related to the observed large ultrasonic sound absorption [15]. Figure 2 shows the Q dependence of the optimized Q (squares) at 13.6 and 9:0 g cm ÿ3 together with sound velocity (dash-dotted lines) obtained by the ultrasonic measurements [7,8]. Also shown are the normalized second frequency moment !…”

Application of the embedded atom model to liquid metals: Liquid mercury

“…The isothermal bulk modulus K T of mercury decreases smoothly upon heating from 25.4 GPa at 293 K and density of 12.55 g/cm 3 to 1.26 GPa at 1673 K and density of 9.25 g/cm 3 . Kozhevnikov et al [33] measured the velocity of sound in mercury on a frequency of 10 MHz at high temperatures and pressures. We can use our data to calculate the isothermal velocity of sound in mercury by the formula u = …”

Structure and thermodynamics of the expanded liquid mercury by Monte Carlo simulation: a first attempt

“…A number of measurements of the physical properties at high temperatures and under high pressures show clearly that a metalnonmetal (M/NM) transition and a thermodynamic liquid-vapor transition occurs as the density decreases. In particular, the behavior of the electronic transport [1,2], the optical reflectivity [3] and the thermophysical properties such as the sound velocity [4,5] and the specific heat [6] provides an insight into the gradual disappearance of the metallic character of expanded mercury in the liquid density range from 11 to 8 g/cm 3 . Theoretical attempts have been made to investigate the transition M/NM in terms of the relativistic contraction, which causes the 6 s 2 closed shell ground electronic state to become chemically more inert due to a lack of overlap between the 6 s and 6 p bands [7].…”