Equilibrium phases of the Bi₂O₃-WO₃ system, synthesized using the citrate-gel method with slow cooling, have been systematically investigated for samples with 22–27 mol% WO₃. Annealing temperature and content of WO₃ were shown to play a significant role in the phases present. Both powder X-ray diffraction and Raman spectroscopy revealed that the room temperature equilibrium phases were 7Bi₂O₃-WO₃ and 7Bi₂O₃-2WO₃, with the latter being dominant. Variable temperature Raman spectroscopy showed that both these phases were present up to 850 °C, with the possible formation of a third unidentified phase at higher temperatures. The ionic conductivities of the mixed-phase materials were between that for the pure 7Bi₂O₃-WO₃ and 7Bi₂O₃-2WO₃ phases and at 700 °C was only about three times lower than that of the pure defect fluorite phase of the 22 mol% WO₃ samples. The Arrhenius plots showed no sudden increase in conductivity between 300 and 750 °C providing evidence that no major phase change occurred in this temperature range.

Bi ₂ O ₃ -WO ₃系统的平衡相，使用缓慢冷却的柠檬酸盐-凝胶法合成，已针对含有 22–27 mol% WO _{3 的}样品进行了系统研究。WO _{3 的}退火温度和含量显示出在存在的相中起重要作用。粉末X射线衍射和拉曼光谱均表明室温平衡相为7Bi ₂ O ₃ -WO ₃和7Bi ₂ O ₃ -2WO ₃，后者占优势。变温拉曼光谱表明，这两种相在高达 850 °C 的温度下都存在，在更高的温度下可能会形成第三个未识别的相。混合相材料的离子电导率介于纯7Bi ₂ O ₃ -WO ₃和7Bi ₂ O ₃ -2WO ₃相之间，并且在700℃时仅比纯缺陷萤石相低3倍左右22 mol% WO ₃样品。Arrhenius 图显示在 300 到 750 °C 之间电导率没有突然增加，这证明在该温度范围内没有发生主要的相变。