Photoemission from ice and water surfaces: Quasiliquid layer effect

Photoemission studies of ice and water have been conducted using uv radiation. The photoemission threshold for both ice near −10°C and water near 10°C is about 1950±50 Å, the emission efficiency for liquid water being about half that for ice. Photoemission from ice decreases steadily with decreasing temperature, apparently without shift in threshold, and vanishes below about −160°C. The results suggest that a waterlike phase is stable on the surface of ice at temperatures above −160°C. It is also concluded that hydroxyl ions which are highly concentrated in the surface phase are responsible for the photoactivity.