Exchange current density of kink atoms

The equilibrium condition for kink atoms requires an equality between the rates of deposition and dissolution, thus forming an exchange current density of kink atoms. From (2.14) for E = follows ... 

According to eq. (2.21), the exchange current density of kink atoms, io,kink. depends on the concentration of kink atoms kink- As long as the surface profile of a crystal face, which depends on the pretreatment and includes an arbitrary number of steps populated by kinks, the exchange current density of kink atoms is not a constant quantity, but depends on step density L or on the surface topography. It cannot be considered as a system property. 

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