Nonpolar (1 0 (1) over bar 0)-oriented ZnO was grown epitaxially on (1 0 0)(MgO) substrate by plasma-assisted molecular beam epitaxy at a high substrate temperature of 600 degrees C. The epilayer was composed of four variant domains which have an orientation relationship with the substrate as: (1 0 (1) over bar 0)(ZnO)//(1 0 0)(MgO) and < 1 <(2)over bar> 1 (3) over bar > (Zno)similar to// < 0 1 1 > (MgO) with a +/- 1.5 degrees deviation. By introducing a Zn0.4Mg0.6O buffer layer, the lattice mismatch was eliminated almost completely based on the extended coincidence lattice model. The crystal quality is therefore improved and the epilayer shows good photoluminescence characteristics. (c) 2013 Elsevier B.V. All rights reserved.