Cage diffusion in liquid mercury

Area of Science:

• Condensed matter physics
• Materials science
• Neutron scattering

Background:

• Understanding atomic dynamics in liquid metals is crucial for materials science.
• Liquid mercury exhibits complex dynamic behavior influenced by interatomic interactions.

Purpose of the Study:

• To investigate the dynamic structure factor of liquid mercury using inelastic neutron scattering.
• To elucidate the diffusion mechanisms governing atomic motion in liquid mercury at room temperature.

Main Methods:

• Inelastic neutron scattering (INS) measurements.
• Analysis of the dynamic structure factor S(q,E) across a range of wave numbers (0.3 < q < 7.0 A⁻¹).

Main Results:

• The incoherent part of S(q,E) is governed by self-diffusion.
• The coherent part of S(q,E) displays characteristics of cage diffusion.
• A quasielastic mode with cage diffusion timescales was observed, but with significantly higher intensity.

Conclusions:

• Atomic motion in liquid mercury involves both self-diffusion and cage diffusion.
• The enhanced intensity of the quasielastic mode suggests a valence fluctuation mechanism may amplify cage diffusion at small wave numbers.