Steps and facets on annealed LaA103 { 100} and { 110} surfaces

Lanthanum-aluminate (LaA103) is one of the optimum substrates for epitaxic growth of thin oxide films. In this paper, the structures of the {100} and {110} surfaces of annealed LaA103 are studied using reflection electron microscopy (REM). (010) steps have been observed on {100}, these are the lowest energy steps. The {100} surface is atomically flat, but the {110} surfaces exhibit high-density fine structures distributed on large surface terraces. These fine structures correspond to the formation of small width (100) and (010) facets on the (110) surface. A growth model is given to interpret the formation of large steps and large terraces on the {110} surfaces.