[en] Partial pressures of Li(g), LiO(g), Li₂O(g) and O₂(g) over Li₂ZrO₃(s) have been determined by a mass-spectrometric Knudsen effusion method. Over various lithium-containing oxides, the partial pressures of Li₂O(g) decrease in the following order: Li₂O>Li₅AlO₄≅Li₄TiO₄≅Li₈PbO₆>Li₂SnO₃>Li₄SiO₄>Li₂TiO₃≅Li₂ZrO₃>LiAlO₂≅Li₂SiO₃>LiNbO₃. From the gas-solid equilibria, enthalpies of formation for Li₂ZrO₃(s) from elements and from constituent oxides have been calculated to be Δ_fH₂₉₈ (Li₂ZrO₃, s)=-(1742.3±8.8) kJ mol^-1 and Δ_foxH₂₉₈/degee(Li₂ZrO₃, s)=-(6.1±92) kJ mol^-1, respectively. Enthalpies of the reaction for adding 1 mole of Li₂O(s) to various oxides decrease with increasing the Li₂O molar content. The results show that the oxides with less Li₂O molar content have more ability to stabilize the pseudo-Li₂O component for lithium aluminates, silicates, titanates, molybdates, ferrates and zirconates. (orig.)