Morphology and microstructure of the Ar+-ion sputtered (0001) α-Al2O3 surface

The morphology and microstructure of Ar+-ion bombarded (0001) alpha-Al2O3 surfaces were studied by employing analytical electron microscopy (AEM) and high-resolution transmission electron microscopy (HRTEM). Surface bombardment with 1 keV Ar+-ions resulted in the formation of a ca. 3-nm thick gamma-Al2O3 layer with a high density of structural defects. A well-defined epitaxial orientation relationship between the gamma-Al2O3 layer and the substrate was observed: (0001)(alpha) parallel to (111)(gamma), [<10(1)over bar 0>], parallel to [110](gamma), and [<11(2)over bar 0>](alpha) parallel to +/-[<11(2)over bar >](gamma). (C) 2000 Published by Elsevier Science B.V.