Skin Bond Relaxation

Surface consisting of a few number of atomic layers forms the skin of a substance. 

The skin shell forms a high-density phase that is more elastic, stiffer, chemically and thermally less stable with entrapped electrons, and subjective polarization. Bond relaxation happens only in the skin in a radial way. The extent and depth of bond relaxation increase with surface curvature. 

In placing with the conventional concept of surface free energy, the energy density and the atomic cohesive energy in the skin region determine the performance of a surface. 

BOLS notation holds for defects, skins of solids and liquids, as well as molecules 

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Mpemba paradox arises intrinsically from heating and undercoordination induced 0 H-0 bond relaxation. Heat emission proceeds at a rate depending on the initial energy storage, and the skin supersolidity creates the gradients of density, specific heat, and thermal conductivity for heat conduction in Fourier s equation of fluid thermodynamics. 

Abstract Atomic hetero- and under-coordination, mechano- and thermo-activation relax the bonds, energy density, and cohesive energy, which discriminate defects, liquid and solid skins, nanostructures from the bulk in the elasticity, plasticity, and mechanical strength. 

Variation of atomic CN, pressure, and temperature relax the bond length and bond energy with an association of densification of charge, energy, and mass. Multiple fields coupling takes place in the skin region. 

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