Change of work function

Fig. 5. Change of work functions of Ag-Pd alloy films caused by CO chemisorption as a function of overall composition. From Bouwman et al. (15).

When the sulfates of alkali metals are added to the vanadium pent-oxide both catalytic activity and electroconductivity increase 19). When vanadium pentoxide is promoted by the sulfates of various alkali metals, no dependence of the change in catalytic activity on the change of work function can be observed (Fig. 10). For instance, the... 

Changes of work function also prove this 122). That adsorbed oxygen is essential for facets is shown also by the fact that desorption of the oxygen causes reversion to the original flat surface orientation. The clean W(lll) surface itself is stable to prolonged heating in vacuum at 2200°K and to short flashes at 2700°K [206). 

Figure Bl.26.24. The change of work function of the (100) plane of tungsten covered by Na, K and Cs, and work function of alkali metals (dashed-dotted line) versus adatom concentration n (Kiejna A and Wojciechowski 1981 Prog. Surf. Sci. 11 293-338). 

Change of Work Function with Particle Size... 

Figure 5.7. The change of work function of Rh(111) upon CO adsorption as a function of coverage [54].

The particular behavior of Pt and Au can be traced back to the relativistic stabilization of s orbitals. This results in an increase of the electron affinity of these elements compared to the lighter atoms. Whereas for Cu, Ag, and nonrelativistic Au, atomic electron affinities of 1.2, 1.4, and 1.1 eV were calculated, a relativistic value of 2.3 eV was obtained for Au [273]. The electron affinity of a Pt atom increased from 0.8 to 1.3 eV due to relativistic effects. This strong change of electronegativity rationalizes the opposite surface dipole and the change of work function observed in experiment [271] for adsorbed Au and Pt compared to the lighter metals. 

Work Function Dependence on Radius and Charge of Aerosol Particles. Give your physical interpretation of relation (2-105) for work function dependence on radius and charge of aerosol particles. Consider separately cases of conductive and non-conductive materials of the macro-particles. Estimate the relative change of work function for a metal particle with 0 = 4 eV, radius 10 p.m, and positive charge 100 e. 

Fig. 15. Resistance R( x) and change of work function 4( (0) observed simnltaneonsly for the same film with a constant rate of flow of H2. Inset Schematic representation of the H/Er phase diagram at 295 K (Muller and Surplice, 1977).

Stegmeier S, Fleischer M, Hauptmann P (2008) Detections of VOCs with activated Pt and supported Pt sensing layers by the change of work function at room temperature. In Proceedings of Eurosensors XXn, Dresden, Germany, September, pp 1424-1427... 

The change of work function corresponds to the bandwidth of the antibonding dipole states, which provides information about the dipole formation and H-like bond formation. Dipole formation widens the bandwidth of the antibonding states and reduces the work function H-like bond formation narrows the antibonding sub-band and restores the work function, which stabilizes the entire system. The reduced work function could be of use in the cold-cathode electron emission but the H-like bond formation effects adversely. 

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