Growth of GaN on nearly lattice matched MnO substrates by pulsed laser deposition

We have grown GaN on nearly lattice matched MnO(1 1 1) substrates by pulsed laser deposition (PLD) and characterized their structural properties using reflection high-energy electron diffraction (RHEED), atomic force microscopy (AFM), and grazing incidence-angle X-ray reflectivity (GIXR). RHEED observation has revealed that the single crystal GaN(0 0 0 1) grows on MnO(1 1 1) and its in-plane epitaxial relationship is GaN [1 1 2̄ 0]//MnO [1 1̄ 0]. The lattice mismatch between GaN and MnO for this alignment is calculated to be 1.6%. From GIXR measurements, the roughness of the hetero-interface between GaN and the MnO substrate was estimated to be 2.3 nm.