thermionic work function

symbol: $W$
https://doi.org/10.1351/goldbook.09297
Parameter describing the apparent work function of a solid that controls the electronic current density, \(J\), emitted from a conductor at temperature \(T\). \(W = -kT\ln(J/AT^{2})\), where \(k\) is the Boltzmann constant and \(A\) is the Richardson constant.
Notes:
  1. For polycrystalline solids, the thermionic work function will be close to the minimum work function of the crystallites present.
  2. Richardson constant, \(A = (4\uppi m_{\rm{e}} k^{2} e)/h^{3} \approx \pu{1.202E6 A m-2 K-2}\) where \(m_{\rm{e}}\) is the mass of the electron, \(e\) the elementary charge, and \(h\) is the Planck constant.
See also: photoelectric work function
Source:
PAC, 2020, 92, 1781. (Glossary of methods and terms used in surface chemical analysis (IUPAC Recommendations 2020)) on page 1817 [Terms] [Paper]
Citation: 'thermionic work function' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. https://doi.org/10.1351/goldbook.09297 RIS BibTex EndNote
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