Published online by Cambridge University Press: 22 February 2011
Reflection electron microscopy (REM) was applied to image in-situ the dynamic changes of atomic-height steps on the surfaces of a-alumina bulk crystals heated to high temperatures. Atomic diffusion, desorption and adsorption processes on cleaved a-alumina (012) surfaces were directly observed at temperatures of 1470 to 1670 K. The surface started to show visible structural changes at 1470–1520 K. The main surface process appears to be atomic desorption, which creates large, flat vacancy-type terraces on the surface.