Activities and phase boundaries in the Cr-Ni system using a solid electrolyte technique

N-type Conductivity in Stabilized Zirconia Solid Electrolytes

“…Results for the free energy of formation of Cr203, determined from emf measurements on the cell Cr-Cr2OJZrO2-CaO/air (IV) at 700~176 (10,36,37), are in excellent agreement with the literature (22). The Cr-Cr203 electrode exerts an oxygen pressure of 10 -21.6 atm at 1000~ (22) and, from Table III and Eq. [2], [4], and [5], }-~ ----0.999 for cell (IV).…”

Thermodynamics of Cr2O3, FeCr2O4, ZnCr2O4, and CoCr2O4

“…Co + Cr 2 O 3 + CO 2 = CO + CoCr 2 O 4 (30) As noted previously, the data of Kunnmann et al [49] Muan [58] appears to be reversed, and the equilibrium for reaction (27) for reaction (26). In a similar manner, the results of Jacob and Fitzner [60] and Koc and Timucin [61] for reaction (27) were converted to free energy changes for reaction (26) by adding the equilibrium for reaction (28) to give ) f G°(1373 K) = -186.79 kJ mol -1 and ) f G°(1573 K) = -160.55 kJ mol -1 , respectively.…”

“…As noted in Table 4, the solid electrolyte results of Tretjakow and Schmalzreid [25] and Pugliese and Fitterer [26] should be ignored because the fO 2 of reaction (15) Among the electrolyte studies performed using an yttria-doped thoria electrolyte there is better agreement but, as pointed out by Anovitz [42], the larger the oxygen fugacity difference between the reference and unknown sides of such cells, the larger the error due to electrode polarization (see also discussion in Worrell [41]). Thus, the data of Holzheid and O'Neill [2] are likely to be closer to the actual values than those of Mazandarany and…”

“…Levitskii et al [62] measured data for reaction (26) relative to the iron-whstite buffer, but provide fitted equations only for the relative Gibbs energy and that of the reaction:…”

“…In a similar manner, the results of Jacob and Fitzner [60] and Koc and Timucin [61] for reaction (27) were converted to free energy changes for reaction (26) by adding the equilibrium for reaction (28) to give ) f G°(1373 K) = -186.79 kJ mol -1 and ) f G°(1573 K) = -160.55 kJ mol -1 , respectively.…”