Using a Mg-Zn composite target, ternary compound Zn1-xMgxO thin films were prepared by direct current (DC) reactive magnetron sputtering on quartz and soda-lime glass substrates at different temperatures. The atomic ratio between Mg and Zn in the films was approximately equal to the area ratio in the target. Pure (111) oriented growth of Zn1-xMgxO thin films with cubic structure was obtained for Mg atomic fraction xgreater than or equal to0.80 and substrate temperature as low as 200degreesC. The band gap of Zn1-xMgxO can be varied from 3.27 eV to levels above 5.3 eV by controlling the Mg area fraction in target. Zn1-xMgxO thin films deposited on glass substrates with this technique may have potential applications in opto-electronic devices. (C) 2003 Elsevier B.V. All rights reserved.