Y-doped BaZrO₃ (BZY) is a promising candidate for electrolytes in protonic ceramic fuel cells. To achieve the high proton conductivities of sintered electrolyte membranes, the poor sintering nature is one of the problems because of the high resistance at grain boundaries. To obtain single-phase BZY with sufficient grain growth (> 1 μm), the information of phase stable conditions of BZY is important. However, in previous studies, there are discrepancies in the single-phase composition range of BZY, and the phase relationships between BZY and other phases at a sintering temperature (1600 °C). In this work, we clarified the phase stable conditions of BZY by reexamining the critical part of the phase diagram of the BaO-ZrO₂-Y₂O₃ system. Based on X-ray diffraction, at certain temperatures below 1600 °C, the single-phase composition range of BZY is not continuous at ~ 10% in the molar ratio of Y/(Zr + Y). Even when sintering at 1600 °C, this separate region probably retards the formation of single-phase and grain growth. Besides, we revealed the other ternary phases, i.e., γ phase and Zr-substituted Ba₃Y₄O₉ are stable in X_BaO < 50 mol% and can coexist with BZY at 1600 °C. This information is discussed on the Gibbs triangles and should be useful for all researchers working on BZY.

掺Y的BaZrO ₃（BZY）是质子陶瓷燃料电池中电解质的有希望的候选者。为了获得烧结的电解质膜的高质子电导率，由于晶界处的高电阻，差的烧结性质是问题之一。为了获得具有足够晶粒长大（> 1μm）的单相BZY，BZY的相稳定条件信息非常重要。然而，在先前的研究中，在烧结温度（1600°C）下，BZY的单相组成范围以及BZY与其他相之间的相关系存在差异。在这项工作中，我们通过重新检查BaO-ZrO ₂ -Y ₂ O ₃相图的关键部分来阐明BZY的相稳定条件。系统。基于X射线衍射，在1600°C以下的某些温度下，BZY的单相组成范围在Y /（Zr + Y）的摩尔比约为10％时不连续。即使在1600°C烧结时，该独立区域也可能会阻碍单相和晶粒生长的形成。此外，我们揭示了其他三元相，即γ相和Zr取代的Ba ₃ Y ₄ O ₉在X _BaO <50 mol％时稳定，并且可以在1600°C与BZY共存。该信息在Gibbs三角形上进行了讨论，对所有从事BZY研究的研究人员都应该有用。