We present a study of the synthesis of epitaxial V2O3 films on c-plane Al2O3 substrates by reactive dc-magnetron sputtering. The results reveal a temperature window, at substantially lower values than previously reported, wherein epitaxial films can be obtained when deposited on [0001] oriented surfaces. The films display a metal-insulator transition with a change in resistance of up to four orders of magnitude, strongly dependent on the O2 partial pressure during deposition. While the electronic properties of the films show sensitivity to the amount of O2 present during deposition of the films, their crystallographic structure and surface morphology of atomically flat terraced structures with up to micrometer dimensions are maintained. The transition temperature, as well as the scale of the metal-insulator transition, is correlated to the stoichiometry and local strain in the films controllable by the deposition parameters.Vanadium sesquioxide, V 2 O 3 , is a transition metal oxide which undergoes a first order structural phase transition (SPT) from a high temperature metallic state to a low temperature insulating state. During this structural transition the crystal structure of the film changes from a rhombohedral phase to a monoclinic phase and has been reported to exhibit a nanotextured phase coexistence in thin film form. 1 The structural transition is linked to the metal-insulator transition (MIT) and can be observed through the resistivity of the material. For bulk V 2 O 3 , the transition temperature is around 155 K. However, for V 2 O 3 thin films grown on single crystal substrates the temperature and magnitude of the MIT can vary with the choice of deposition method and conditions, substrate material and surface orientation. 2-4 The controlling materials parameters involved in these cases include strain in the film, induced by the lattice mismatch between V 2 O 3 and substrate material, 5 the amount of vanadium and oxygen deficiencies, 6 crystalline defects, and structural disorder. 7 Tunability of the metal-insulator transition by stoichiometry in bulk V 2−x O 3 has been observed where the increase in oxygen content shifts the MIT to lower temperatures and fully suppresses the transition for x > 0.026. 8 A similar suppression of the MIT has been reported in Cr doped V 2 O 3 thin films grown on Al 2 O 3 [0001] surfaces and attributed to Cr promoting oxygen excess in the films, stabilizing the metallic state. 9 In this paper we present a study of the structural and electronic properties of V 2 O 3 thin films fabricated on Al 2 O 3 [0001] substrates by reactive dc-magnetron sputtering. Controlling the oxygen partial pressure and substrate temperature during growth, we obtain epitaxial thin film layers of V 2 O 3 showing low roughness terraced surfaces. The structural quality of the films is linked to the substrate temperature during deposition and resilient to changes in the O 2 partial pressure during deposition. However, we observe a strong dependence of the magnitude and temperature of the MIT on the O...