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Layering at liquid metal surfaces and interfaces: Friedel oscillations and confinement effects

Brent G. Walker·Nicola Marzari·Carla Molteni
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Abstract

The structures of the liquid surface and the liquid-solid interface of sodium have been characterized with extensive first-principles molecular dynamics simulations. Friedel oscillations in the electronic charge density at the free surface were found to persist across the solid-to-liquid melting transition, with a small but distinctive electronic layering that remains decoupled from the atomic positions. Strong ionic layering was observed both at the liquid surface and at the liquid-solid interface, notwithstanding the absence of Friedel oscillations or under-coordinated atoms in the latter case. Confinement effects at these soft or hard boundaries drive the atoms into quasi-close-packed layers; even for this prototypical free-electron metal Friedel oscillations are not relevant to ordering.

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Brent G. Walker, Nicola Marzari, Carla Molteni. 2005-09-23. Layering at liquid metal surfaces and interfaces: Friedel oscillations and confinement effects. https://arxiv.org/abs/cond-mat/0509609

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