Phase Equilibria in the Ferrite Region of the System Fe—Co—O

Phase relations in the system Fe‐Co‐O have been determined between 1000° and 1300°C in oxygen pressures of 0.01 to 20 atm. Only the portion of the system between CoFe 2 O 4 and Co 3 O 4 was considered in order to determine those conditions under which a complete series of solid solutions could be prepared. No field width on either side of oxygen stoichiometry was detected for solid solutions between CoFe 2 O 4 and Co 3 O 4 .