The potential use of beta-Ga2O3 wafers as transparent conductive substrates for compounds with hexagonal structure, in particular the GaN-system, is shown. Nitridation of the main cleavage plane under high temperature and NH3 gas results in the substitution of O by N on the surface, and a simultaneous surface reconstruction. The 2-fold symmetry of the initial (100) plane changes to a 6-fold symmetry, keeping the [010] azimuth as a symmetry direction. The RHEED pattern suggests the formation of GaN on the beta-Ga2O3 surface, with the b-axis of beta-Ga2O3 parallel to the <11 (2) over bar0> direction of GaN, so that beta-Ga2O3 can be used as a substrate with no lattice mismatch to GaN. (C) 2004 Elsevier B.V. All rights reserved.