Volta potential [SEP] named after
Alessandro Volta.
Volta potential between two metals.
When two metals are electrically isolated from each other, an arbitrary potential difference may exist between them. However, when two different neutral metal surfaces are brought into electrical contact (even indirectly, say, through a long wire), electrons will flow from the metal with a higher Fermi level to the metal with the lower Fermi level until the Fermi levels in the both phases are equal.
Once this has occurred, the metals are in thermodynamic equilibrium with each other
Volta potential
The Volta potential (also called Volta potential difference, contact potential difference, outer potential difference, Δψ, or "delta psi") in electrochemistry, is the electrostatic potential difference between two metals (or one metal and one electrolyte) that are in contact and are in thermodynamic equilibrium. Specifically, it is the potential difference between a point close to the surface of the first metal, and a point close to the surface of the second metal (or electrolyte).
The Volta potential is named after