Investigation of the vaporization of BaUO3 by means of mass spectrometry

An investigation of the vaporization of BaUO3 has been carried out for the first time by means of Knudsen effusion mass spectrometry in the temperature range of 1770-1920 K. The main vapor species over BaUO3 were BaO(g), Ba(g) and UO2(g) in decreasing order of their pressures. The standard enthalpy of formation of BaUO3 was evaluated by the second law and the third law treatments, in which the estimated H-0(T)-H-0(298.15) and gef(T) values were employed on account of the absence of published data. Considering the compounds of BaMO(3) with the same perovskite structure where M stands for metallic cations with the valence of four, a comparison of their standard enthalpies of formation was made in relation to the ionic radius of M(4+).