Azimuthal Anisotropy of Rhombohedral (Corundum Phase) Heterostructures

Abstract

The corundum structure is rhombohedral/trigonal and thus has lower symmetry than the well-investigated hexagonal crystals such as wurtzite GaN- and ZnO-based materials. By investigating the growth of α-phase (Formula presented.) alloy thin films on various orientations of Al2O3 substrates, the anisotropy around the [00.1]-axis is investigated. In particular, the pseudomorphic growth on the r plane (01.2) and (Formula presented.) (10.2) plane substrates is compared. The findings agree with elasticity theory. Also, different growth kinetics are found on these two planes in terms of growth rate and preferential cation incorporation.