Phase equilibria and X-ray diffraction investigation of the system Cu-Fe-O.
Schaefer SC; Hundley GL; Block FE; McCune RA; Mrazek RV
Metall Trans 1970 Sep; 1(9):2557-2563
An equilibria investigation for the system cu-fe-o determined nine regions of stability which were investigated in the oxygen pressure range of 1 x 10-4 to 5 x 10-1 atm (p total = 1 atm) and at temperatures of 1,173 deg. to 1,250 deg. K. Oxygen dissociation pressures were determined for three univariant, four bivariant, and two trivariant equilibria. X-ray examination of selected equilibrated samples established conclusively that (1) cuprous ferrite (delafossite) is a stoichiometric compound, (2) cupric ferrite is a solid solution, and (3) solubility of delafossite in cuprous oxide is negligible. A relationship of lattice parameters with compositional variations was determined for the solid solution. Tetragonal-to-cubic spinel crystal transformation of cupric ferrite solid solution occurs with a c/a ratio at or slightly greater than 1.028. A volume discontinuity accompanies the tetragonal-to-cubic spinel transformation, which is a first-order type of thermodynamic transition.
Thermodynamics; Thermodynamic-reactions; Metallurgical-processes; Electronics-industry; Metallic-compounds; Metal-oxides; Metal-industry; Metal-compounds
OP; Journal Article
Metallurgical Transactions. B. Process Metallurgy