Surface Properties of Condensed Matter

Surfaces of condensed phases depart fundamentally from bulk regions in atomic coordination, electronic structure and chemical potential. Atoms in the outermost layer of a solid or liquid lack neighbours on one side, giving rise to excess free energy, surface stress and distinct electronic states. Surfaces readily reconstruct to minimise energy, adopting new periodicities or defect patterns. They also host unique vibrational modes, enhanced catalytic sites and charge‐transfer phenomena. Surface tension in liquids, arising from unbalanced intermolecular forces, governs droplet shapes, wetting and capillarity. In solids, surface energy influences adhesion, fracture toughness and thin‐film growth by determining nucleation barriers and diffusion pathways. Adsorption of atoms and molecules at surfaces involves a competition between physisorption—weak van der Waals forces—and chemisorption, in which covalent or ionic bonds form. Site selectivity (atop, bridge or hollow) is controlled by electronic factors such as the d‐band centre in metals and by geometric factors such as step edges and kink sites. Two‐dimensional electron systems on atomically flat surfaces can enter hydrodynamic regimes, where collective motion emerges from dominant electron–electron scattering. Surface electronic reconstructions, oxide overlayers and adsorbate‐induced dipoles further modify catalytic activity, corrosion resistance and electronic transport. Advances in scanning probe microscopy, synchrotron‐based spectroscopies and first‐principles modelling now permit atom‐resolved insight into surface structure, dynamics and reactivity, paving the way for tailored interfaces in energy conversion, electronics and heterogeneous catalysis.

Research from Nature Portfolio

Experiments on ultraclean topological semimetal flakes revealed a “para-hydrodynamic” transport regime in which weak surface disorder substitutes for electron–electron collisions as the key momentum-conserving process. Adapting kinetic theory to include boundary scattering, researchers showed that an effectively viscous flow persists even with minimal interparticle interactions, consistent with nonlocal transport measurements. In parallel, spectroscopic visualisation of hydrogen spillover in Pd@ZIF-8 metal–organic framework composites exploited coupled X-ray absorption and surface-enhanced Raman methods. Modular signal amplification provided real-time maps of interfacial hydrogen dynamics, uncovering reversible pathways that govern selectivity in semihydrogenation catalysis. More recently, aluminium doping of MgO was demonstrated to open proton–electron diffusion channels on a non-reducible support, enabling H⁺/e⁻ coupled spillover comparable to classical reducible oxides. These findings establish new paradigms in surface-mediated transport and spinoff design rules for catalytic interfaces.

Surface Properties of Condensed Matter publication trend

The graph below shows the total number of articles in surface properties of condensed matter across all publications each year (not limited to Nature Index journals).

Technical terms

Surface tension: Excess free energy per unit area at a liquid interface arising from unbalanced cohesive forces.

Surface reconstruction: Rearrangement of surface atoms into a new periodic pattern to lower surface energy.

Chemisorption: Adsorption involving formation of chemical bonds between adsorbate and surface atoms.

Physisorption: Weak adsorption dominated by van der Waals interactions without significant bond formation.

D-band centre: Energy-weighted average of metal d-states relative to the Fermi level, correlating with adsorbate binding strength.

Hydrodynamic transport: Collective electron flow regime where electron–electron collisions outpace momentum-relaxing processes, yielding viscous behaviour.

Hydrogen spillover: Surface migration of activated hydrogen atoms or protons from metal nanoparticles onto a support, enabling remote hydrogenation sites.

References

1. Surface Physics.
2. Para-hydrodynamics from weak surface scattering in ultraclean thin flakes. Nature Communications (2023).
3. Spectroscopic visualization of reversible hydrogen spillover between palladium and metal–organic frameworks toward catalytic semihydrogenation. Nature Communications (2024).
4. Heteroatom doping enables hydrogen spillover via H+/e− diffusion pathways on a non-reducible metal oxide. Nature Communications (2024).
5. A computational map of the probe CO molecule adsorption and dissociation on transition metal low Miller indices surfaces. Applied Surface Science (2023).
6. Study on the Adsorption Properties and Mechanisms of CO on Nickel Surfaces Based on Density Functional Theory. Energies (2023).