Vaporization processes in the ZnO-SnO2 system have been studied by the Knudsen effusion technique in combination with mass spectrometric analysis of the vapor phase in the temperature range 1360 K to 1460 K. It has been identified by studying the ZnO-SnO2 system in quartz cells that its gas phase mainly consists of Zn(g), O-2 and SnO(g). The partial pressures of the vapor species were determined at 1450 K. The incongruent character of the Zn2SnO4 vaporization was stated, and the p-x projection of the ZnO-SnO2 phase diagram at 1450 K was constructed. The standard molar enthalpy of formation of the mixed oxide Zn2SnO4 at 298 K was found to be -1296.2 +/- 7.5 kJ . mol(-1). (C) 2013 Elsevier Ltd. All rights reserved.