A new candidate single crystal (La,Sr)(Al,Ta)O-3 (LSAT) as a substrate for GaN epitaxial growth was found. Mixed-perovskite (1 1 1) oriented crystals were successfully grown by conventional Czochralski method. Excellent lattice inatching with galliurn nitride inakes this inaterial specially prornising. Deterinination of the lattice paranneters and the phase identification obtained crystals by X-ray diffraction analysis was carried out. Thermal expansion, thermal conductivity and electrical conductivity Were measured. GaN epitaxial layers have been grown on (1 1 1) LSAT substrate and the results are presented. (C) 2002 Elsevier Science B.V. All rights reserved.