The phase stability of the cubic perovskite-type oxide BaCo_0.7Fe_0.2Nb_0.1O_3−δ (BCFNO) has been examined by means of X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). And, the timescale on the second phases has been established by using the TOPAS 4.2. Compared with Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3−δ (BSCFO), for samples annealed at T = 1023 K for t = 64 d, the rhombohedral and hexagonal phases formed on the surface of cubic perovskite BCFNO surface simultaneously and the amount of them is smaller. As for the rhombohedral phase, it comes out firstly along the grain boundary, and whose amount in equilibrium is about 5％. In contrast to the rhombohedral phase, the hexagonal phase is more likely to form at lower temperature which lead to the microcracks. In brief, obtaining the eligible phase stability is crucial for the industrial application of the oxygen permeation membrane.

已通过X射线衍射（XRD），扫描电子显微镜（SEM）和透射电子显微镜（TEM）检验了立方钙钛矿型氧化物BaCo _0.7 Fe _0.2 Nb _0.1 O3 _-δ（BCFNO）的相稳定性。并且，已经通过使用TOPAS 4.2建立了第二阶段的时间表。与Ba _0.5 Sr _0.5 Co _0.8 Fe _0.2 O3 _-δ的比较（BSCFO），对于在T = 1023 K退火t = 64 d的样品，菱形钙钛矿BCFNO表面同时形成了菱形和六方相，并且它们的数量较小。至于菱面体相，它首先沿晶界出现，其平衡量约为5％。与菱形相相反，六角形相更可能在较低温度下形成，从而导致微裂纹。简而言之，获得合格的相稳定性对于氧渗透膜的工业应用至关重要。