Work Function and Surface Structure of Simple Metals

Abstract

The work function is calculated for ten simple metals in the framework of model potentials. The Shaw model potential is used. The surface structure is described b y a model containing a decrease of the conduction electron density and a change of the lattice constant. The parameters of this model are determined from the requirement of a minimum surface energy. The calculated work functions agree well with the experimental ones. The calculated increase of the lattice constant at the surface is about 1%. It gives rise to a decrease of the total surface dipole potential. The latter is much smaller than that calculated for the usual model where the ions are replaced by a homogeneous background. The agreement of the work function with experiment justifies the use of the mean value of model potentials in the calculation of physical properties.Die Austrittsarbeit von zehn einfachen Metallen wurde unter Verwendung des ShawModellpotentials berechnet. Fur die Metalloberflache wurde ein Modell verwendet, das sowohl den Abfall der Elektronendichte als auch eine Anderung der Gitterkonstanten enthalt. Die dieses Modell bestimmenden Parameter wnrden durch Minimalisierung der Oberflachenenergie bestimmt. Es ergab sich eine VergroDerung der Gitterkonstanten a n der Oberfliiche von etwa 1%. Sie fuhrt zu einer Verringerung des gesamten Dipolpotentials der Oberflliche. Letzteres ist wesentlich kleiner als dasjenige, das man fur ein Modell erhllt, bei dem die Ionen durch einen homogenen Untergrund ersetzt sind. Weiterhin laDt die ubereinstimmung der Austrittsarbeit mit den experimentellen Werten den SchluD zu, daO die Verwendung der Mittelwerte von Modellpotentialen bei der Berechnung physikalischer GroDen sinnvoll ist.

Correlation of Electron Work Function and Surface-Atomic Structure of Some d Transition Metals

“…The results of jellium-model-based calculations for twenty nontransition or simple polycrystalline metals by Heine and Hodges [42] and Paasch et al [43], yield generally lower values of the internal contribution, ranging between 3.7 eV for Pb or Hg and 0.8 eV for Al [42]. Comparison to the present values of A 1 for d transition metals, which range from 5.1 eV (Pt : FE) to 3.8 eV (Mo : FE), may be interesting in view of the different categories of metals.…”

Simple Non‐Local Calculation of Jellium Metal Surface Properties

“…Contrary to the calculation of Smith [3] and Sahni and Ma [7], all the energy functionals can be calculated analytically (including the surface correlation energy [22]) and expressed as functions of the parameter 8.…”

Thermal conductance of metal interfaces at low temperatures

“…Initially we neglect the quantum mechanical reflection at the step potential. The current in the z direction is ~2 2e I (13) We assume the electron distribution function at equilibrium to be given stepwise in the two regions by f~~ i=1,2 (14) Then the current of electrons moving from left to right is given in the two regions by J~'-I k~o d3k kz, J~)-I k;'~ko d3k" k: (15) Ikl~kFa lk"l~ kF2…”