Fast sound in expanded fluid Hg accompanying the metal-nonmetal transition
Fast sound in expanded fluid Hg accompanying the metal-nonmetal transition
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DOI：
10.1103/physrevlett.93.097801
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发表时间：
2004-08-27
影响因子：
8.6
通讯作者：
Baron, AQR
中科院分区：
文献类型：
--
作者：
Ishikawa, D;Inui, M;Baron, AQR
用高分辨率非弹性X射线散射测量了膨胀流体汞的动态结构因子S(q，omega)，测量范围为9.0g cm(-3)(1723K和1940bar)，动量转移Q为0.2-4.8埃。在广义流体力学框架下的分析表明，集体激发的频率随Q的增加比从宏观声速估算的频率增加得更快。由频散关系估算的9.0g cm(-3)处的有效声速是超声声速的三倍。这一结果表明，伴随着金属-非金属转变的膨胀流体汞中存在快声。
The dynamic structure factor S(Q,omega) of expanded fluid Hg has been measured up to the metal-nonmetal transition region at 9.0 g cm(-3) (1723 K and 1940 bars) using high-resolution inelastic x-ray scattering, at momentum transfers, Q, from 0.2 to 4.8 Angstrom(-1). Analysis in the framework of generalized hydrodynamics reveals that the frequencies of the collective excitations increase faster with Q than estimated from the macroscopic speed of sound. The effective sound velocity at 9.0 g cm(-3) estimated from the dispersion relation is triple the ultrasonic sound velocity. The present result suggests the existence of fast sound in expanded fluid Hg accompanying the metal-nonmetal transition.