ABSTRACT
A material that does not have flowability at temperatures below its melting point can exist as a solid in various shapes. The significant feature is the degree of the unsaturation of the chemical bond to which the internal structure terminates when the surface of the solid is looked at on the microscopic scale. It is not possible to diffuse because the activation energy of the surface diffusivity is generally high, when the adjacent potential energy is different by atoms, ions, or molecules that compose the surface. Therefore, a feature of the solid surface is that it is not able to produce a uniform energy like the liquid surface. Various characteristics of a solid surface are strongly influenced by these two features.
