A reconstruction of the polar NiO(111) surface predicted by D.Wolf using low-energy electron diffraction was studied. Thin NiO films (10 to 20Å) were used as substrates. As prepared, the films with a p(1 x 1) NiO(111) structure were covered with hydroxyl groups, which could be removed by a simple heat treatment. As the hydroxyl groups were desorbed, the surface reconstructed; exhibiting a diffuse p(2 x 2) structure. Re-adsorption of water onto the reconstructed surface lifted the reconstruction and again led to the formation of the p(1 x 1) hydroxyl covered surface.

Hydroxyl Driven Reconstruction of the Polar NiO(111) Surface. F.Rohr, K.Wirth, J.Libuda, D.Cappus, M.Bäumer, H.J.Freund: Surface Science, 1994, 315[1-2], L977-82