Atomic force microscopy study of the faceting on MgO(110) surface

Abstract

Using atomic force microscopy, we have studied the morphologies of the MgO(110) surface. After annealing at 650 °C, this surface facets into elongated triangular mesoscale islands along the [001] direction. A statistical counting of both the widths and the heights of these islands can be well fitted by a Gaussian normal distribution. The most popular island width and height are ∼1200 and 140 Å, respectively, indicating that these faces are roughly (350). The formation of (350) plans, instead of (100), is believed due to a kinetic reason. Besides, both Gaussian distributions are much narrower than predicted for the microscopic terrace-step-kink model. This result may suggest that an island–island interaction is fundamentally different from a step–step interaction.