The coexistence of g(g0) and u alumina observed by STM and LEED on top of oxide layer grown on CoAl(1 0 0)

We report the coexistence of g(g0) and u alumina grown on the CoAl(1 0 0) surface. Both phases were observed after annealing of alumina at 1150 K by means of scanning tunnelling microscopy (STM). The crystal structures of g(g0) and u alumina were indexed based on low energy electron diffraction (LEED) and STM experimental data.