The effective image plane on metal surfaces

The surface potential, Xm due to the interfadal dipole of the electron tailing away from the metal surface is given as a function of the excess or defidt of metal electrons in Eqn. 5-27  

The plane of the center of mass of induced image charge, oJ,x), is called the effective image plane [Lang-Kohn, 1973], and its position, Xm, is given by Eqn. 5-28  

As shown in Fig. 5-20, the effective image plane is located close to but away from the jellium metal edge. CombiiungEqns. 5-27 and 5-28 yields the surface potential Xm as a fiinction of Om in Eqn. 5-29  

In calculating the distribution of image charge aj.x), we use an improved jellium model in which the quasi-potential due to the lattice ions is taken into 

In a range of potential where the interfacial charge is relatively small, the electric capacity, Cm, due to the electron tailing from the metal side is, to a first approximation, represented hy the capacity of a parallel plate condenser of thickness Xim as shown in Eqn. 5-30  

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