The equilibrium oxygen pressure over the Cr-Y2O3-YCrO3 coexistence measured with the galvanic cell using stabilized ZrO2 solid electrolyte

The equilibrium oxygen pressure over the Cr-Y2O3-YCrO3 coexistence has been measured by the following cells: Cr, Y2O3, YCrO3 \ ZrO2 \ Cr, Cr2O3 [I] Mn, MnO \ ZrO2 \ Cr, Y2O3, YCrO3 [II] Moreover, the partial electronic conduction parameter, P-e, has been determined simultaneously, as the oxygen partial pressure where the n-type electronic and ionic conductivities are equal in the stabilized ZrO2. The equilibrium oxygen pressure, P-O2, over the Cr-Y2O3-YCrO3 coexistence and P-e are expressed as log (P-O2/atm) = 10.6 - 4.39 x 10(4) 1/T +/- 0.1 (1385 to 1470 K) log (P-e/atm) = 8.86 - 4.21 x 10(4) 1/T +/- 0.3 (1385 to 1470 K) From the equilibrium oxygen pressure and the standard Gibbs energy of formation of Y2O3, the standard Gibbs energy of formation of YCrO3 is calculated as Delta G(f) degrees/J mol(-1) = -1.58 x 10(6) + 2.93 x 10(2) T +/- 7 x 10(3) (1385 to 1470 K)