Ionization on Platinum and Tungsten Surfaces. I. The Alkali Metals

The ionization of all of the alkali metals on tungsten and on tungsten oxide surfaces follows the Saha‐Langmuir equation with no reflection. On platinum, however, a departure from this equation indicates partial reflection of the atoms. The reflection of Na is probably 0%, since the ionization efficiency is given closely by the Saha‐Langmuir equation with a value of 5.50 ev for the work function of Pt at 2000°K. The same value of the work function then indicates reflections of 18% for Li, 48% for K, 22% for Rb, and 8% for Cs, at 2000°K.