Volta potential

This compensating voltage is the negative of the Volta potential.

The total charge over each objects' surface depends on the capacitance between the two objects, by the relation where is the Volta potential.

Just like the work function, the Volta potential depends sensitively on surface state, contamination, and so on.

The Volta potential can be significant (of order 1 volt) but it cannot be measured directly by an ordinary voltmeter.

The Volta potential is named after Alessandro Volta.

At thermodynamic equilibrium, it is typical for electrical potential differences of order 1 V to exist in the vacuum (Volta potentials).

Measurement of Volta potential (Kelvin probe)

The Volta potential of a metal surface can be mapped on very small scales by use of a Kelvin probe force microscope.

These equilibrium variations in ϕ (called Volta potentials or contact potential differences) can disrupt sensitive apparatus that rely on a perfectly uniform vacuum.

In electrochemistry there are Galvani potential, Volta potential, electrode potential, standard electrode potential.

The Volta potential is not an intrinsic property of the two bulk metals under consideration, but rather is determined by work function differences between the metals' surfaces.

The Volta potential however corresponds to a real electric field in the spaces between and around the two metal objects, a field generated by the accumulation of charges at their surfaces.

In this case the capacitance change is not known - instead, a compensating DC voltage is added to cancel the Volta potential so that no current is induced by the change in capacitance.

Volta potential (also called Volta potential difference, or contact potential difference, or outer potential difference, Δψ, delta psi) in electrochemistry, is the electrostatic potential difference between two points ("1" and "2") in the vacuum: