抄録
The properties of thin films, deposited onto clean metal surfaces by evaporation from barium oxide cathode, were studied simultaneously by means of photo-electric and thermionic procedures. Both photoelectric and thermionic emission had close dependence upon the concentration of atomic barium in the barium oxide source cathode. So far as the deposited layer was very thin, the spectral distribution of photo-emission fitted well to Fowler’s plot, but as the layer became thicker, semiconductor type photo-emission appeared gradually. The maximum sensitivity of photo-emission from several molecular layers of BaO displaced 2.72 to 2.30 ev., together with the decrease in thermionic work function from 1.7 to 1.0 ev by increasing barium density of the layer.
