Evidence for oxygen underlayer formation at near‐liquid‐nitrogen temperatures on Zr(0001)

When a clean Zr(0001) crystal is exposed to oxygen at 82 K, the work function initially decreases by ∼250 mV for an exposure of 0.7 to 0.8 L. Annealing this surface to ∼550 K produces a further decrease in work function of ∼300 mV, and a ‘‘(2×2)‐like’’ low‐energy electron diffraction pattern is observed. The initial decrease in work function upon oxygen adsorption at 82 K is believed to be due to oxygen incorporation into the Zr lattice.