A chemical potential diagram for A‐B‐O (A, B = metallic elements) systems has been constructed to make visually clear the thermodynamic stability of double oxides; the stability area of metallic elements, their binary oxides, and double oxides can be presented as convex polygons in a log (aA/aB) vs log P(O2) plot, a and P(O2) being the activity of metallic elements and the oxygen partial pressure, respectively; the axis variable, log (aA/aB), is used to treat two metallic elements equivalently. The Co‐Ti‐O and La‐Co‐O systems have been chosen as examples to demonstrate how the present diagram can provide complicated phase relations in a compact and visualized manner. An attempt has also been made to utilize this diagram to present graphically products of kinetic decomposition of double oxides placed in an oxygen potential gradient.
|Number of pages
|Journal of the American Ceramic Society
|Published - 1989 Nov