The synthesis of ternary oxides strongly depends on the stability of the corresponding binary metal oxides. Therefore, the decomposition into different metal oxides or pure elemental phases needs to be addressed. The probability of decomposition in competing compounds can be minimized by controlling the chemical potentials as in (9), which directly correspond to temperature and pressure. Figure shows the stability region for CBO and CFO, respec- The area above the copper oxide lines is favorable for decomposition into CuO and Cu 2 O, respectively. The region below the lines, corresponding to the binary iron oxides FeO, Fe 2 O 3 , and Fe 3 O 4 indicates decomposition into these iron oxides. This leaves an area from about 800 K to almost 1700 K as the stability region for the CFO. According to the calculated stability region, CFO forms at higher temperatures, but there are also studies showing that CFO exists at ambient temperatures, probably as meta-stable phase. This observation indicates the existence of a high energy barrier, preventing the decomposition of CFO to its binary oxide compounds.