Adsorption and Work-Function Studies

Continuing these investigations, Becker (21, ), showed that (1) Cs was 

The adsorption of O2 on W has been investigated by Kingdon, 66). In this case, the temperature required to produce a satisfactory emission current was also sufficient to evaporate O2 from the filament at a measurable rate, and additional O2 was continuously supplied to the filament to compensate for the loss. The results were difficult to interpret, but Reimann 57) used the data to show that the adsorption of O2 on W increased the work function of W by 1.75 v. at 1500° K. 

One of the earliest determinations of the change of photoelectric work function of a metal surface due to adsorption was made by Ives and Olphin 

Suhrmann (71, 72) has also confirmed some of the results obtained by C.P.D. methods (7S) for the adsorption of H2 and Xe on evaporated Ni films. As seen in Fig. 16, when Hz was added to an unsintered Ni film at 90° K, the work function initially increased, but at higher coverages each dose of gas produced a positive drift in potential. The maximum S.P. was —0.39 V., falling to —0.21 v. at a pressure of 10 mm. Hg. To account for 

Change in photoelectric yield on the adsorption of hydrogen on an unsintered nickel surface. 

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