Potentials, Surface Potential Differences, and the Thermionic Work Function

Volta Potentials, Surface Potential Differences, and the Thermionic Work Function 

When two dissimilar metals are connected, as illustrated in Fig. V-16, ]here is a momentary flow of electrons from the metal with the smaller work function to the other so that the electrochemical potential of the electrons becomes the same. For the two metals a and /3 

The difference in Volta potential AV, which has been called the surface (or contact) potential in this book, is then given by 

It is this potential difference that is discussed in Chapter IV in connection with monomolecular films. Since it is developed in the space between the phases, none of the uncertainties of phase boundary potentials is involved. 

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