Thermodynamics, Statistical Physics, and Quantum Mechanics

THERMODYNAMICS AND STATISTICAL PHYSICS 235

The current

where is the electron charge. Therefore, we can express P from (S.4.103.5):

Equating (S.4.103.6) with (S.4.103.3), we find the current

Alternatively, we cancalculate thecurrent byconsidering the electrons

leaving the metal as if theyhave akinetic energy high enough toovercome

the potential barrier.

b) For one particle,

where and are theenergies, and and thevolumes per particle,

of the gas and solid, respectively.Since we canrewrite (S.4.103.8)

in the form

Substituting(S.4.103.9)into theClausius-Clapeyronequation (seeProblem

we obtain

We may rewrite(S.4.103.11) as

Integrating,we recover (S.4.103.2):

whereAis someconstant, or

4.57),