Conjugated bilayer structure of the homogeneous solid-liquid interface of metals

Area of Science:

• Materials Science
• Physical Chemistry
• Condensed Matter Physics

Background:

• The traditional
• interfacial region
• concept for homogeneous solid-liquid (SL) interfaces lacks detailed structural understanding.
• Previous models struggle to explain the diffuse nature and energy contributions of these interfaces.

Purpose of the Study:

• To elucidate the intrinsic structure of homogeneous metal solid-liquid interfaces.
• To propose a new structural model that explains interfacial properties.
• To re-evaluate the origins of interfacial free energy.

Main Methods:

• Molecular dynamics simulations were employed to investigate the atomic structure of SL interfaces.
• Analysis focused on identifying distinct layers and their interactions at the interface.

Main Results:

• The intrinsic structure of homogeneous SL interfaces is a conjugated bilayer structure (CBS), comprising interfacial solid (IS) and interfacial liquid (IL) layers.
• The CBS exhibits a four-terrace nature, with stepwise transitions between bulk solid and liquid phases.
• Interfacial free energy primarily arises from the potential energy increase in the IS layer, not liquid entropy loss.

Conclusions:

• The conjugated bilayer structure (CBS) is the fundamental structure of homogeneous metal SL interfaces.
• CBS explains the diffuse nature of the interfacial region and accurately locates the intrinsic surface.
• This model resolves limitations of the traditional
• interfacial region
• concept and provides a clearer understanding of interfacial energy.