Work functions of elements expressed in terms of the Fermi energy and the density of free electrons

Citation
S. Halas et T. Durakiewicz, Work functions of elements expressed in terms of the Fermi energy and the density of free electrons, J PHYS-COND, 10(48), 1998, pp. 10815-10826
Citations number
21
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
JOURNAL OF PHYSICS-CONDENSED MATTER
ISSN journal
09538984 → ACNP
Volume
10
Issue
48
Year of publication
1998
Pages
10815 - 10826
Database
ISI
SICI code
0953-8984(199812)10:48<10815:WFOEEI>2.0.ZU;2-F
Abstract
On the basis of Brodie's definition of the work function and the length of spontaneous polarization of plasma, the following new formula for calculati on of the work functions of elements has been derived: phi/eV = 43.46 alpha r(s)(-3/2) (E-F/eV)(-1/2), where r(s) is the electron density parameter ex pressed in units of the Bohr radius, EF is the Fermi energy and alpha is an empirical constant (alpha = 0.86 for the alkali metals, Ca, Sr, Pa Ra and Tl, whereas alpha = 1.00 for the remaining elements). The density parameter was calculated from the atomic mass, the bulk density of the element and t he assessed number of free electrons per atom which is equal to the nominal valence of the element or, in the case of transition metals, close to this number (within +/-0.5). The values obtained by using the above formula are in excellent agreement w ith experimental data for pure-metal polycrystalline surfaces, within 5% in most cases. A table with the work functions and with complete input data f or most of the elements is presented.