โ Scribed by G. F. S.
No coin nor oath required. For personal study only.
CURRENT TOPICS.
[J. F. I.
light. Platinum displayed a mere trace of change. " Copper showed a very definite and instantaneous decrease in resistance under the influence of light for the thinnest films used, I. 5 x io -6 on1. in thickness. The decrease was found' to be between I.I and 1.6 parts in Io ~ for different films. Palladium and bismuth showed much larger changes, amounting to I4 and I6 parts in Io 6, respectively. Tellurium films, sensitive at room temperature, showed a considerable increase in sensitivity at liquid air temperature, in agreement with the prediction of theory. These results conform rather well with predictions. The evidence appears, then, to support Waterman's prediction of a light sensitivity for metals at low temperatures." The behavior of bisnmth was erratic.
The lowest temperature was that of liquid air. The author holds that the size of the changes in resistance could be augmented by the use of lower temperatures, thinner films and, shorter wave-lengths.
G. F. S.
๐ SIMILAR VOLUMES
CURRENT TOPICS. [J. F. I. been found recently that metal surfaces carefully freed from gases do not exhibit any appreciable photo-electric effect. It seems therefore, as if the process of electronic emission from cold metal surfaces could take place only through the intermediary of the surface-lay