TY - JOUR
T1 - The CrCr2O3 oxygen buffer and the free energy of formation of Cr2O3 from high-temperature electrochemical measurements
AU - Holzheid, A.
AU - O'Neill, H. St C.
N1 - Copyright:
Copyright 2014 Elsevier B.V., All rights reserved.
PY - 1995/2
Y1 - 1995/2
N2 - The free energy of formation of Cr2O3, defined by the reaction 2 Cr + 3 2 O2 = Cr2O3 has been measured electrochemically using a yttria-doped thoria (YDT) solid electrolyte, in the temperature range from 900 to 1400 K. Fe + "FeO" was used as the reference electrode. The results have been combined with high temperature heat capacity data from the literature, to give, in J · mol -1 μO2(±170) = -758.585 + 349.718T -25.5216T + 0.00935T2 (600 K < T < 1800 K). Our results are not in good agreement with the calorimetric data and imply that the currently accepted calorimetric value for the entropy of Cr2O3 at 298.15 K may be too low by 4.6 J/K · mol.
AB - The free energy of formation of Cr2O3, defined by the reaction 2 Cr + 3 2 O2 = Cr2O3 has been measured electrochemically using a yttria-doped thoria (YDT) solid electrolyte, in the temperature range from 900 to 1400 K. Fe + "FeO" was used as the reference electrode. The results have been combined with high temperature heat capacity data from the literature, to give, in J · mol -1 μO2(±170) = -758.585 + 349.718T -25.5216T + 0.00935T2 (600 K < T < 1800 K). Our results are not in good agreement with the calorimetric data and imply that the currently accepted calorimetric value for the entropy of Cr2O3 at 298.15 K may be too low by 4.6 J/K · mol.
UR - http://www.scopus.com/inward/record.url?scp=0000691835&partnerID=8YFLogxK
U2 - 10.1016/0016-7037(94)00287-V
DO - 10.1016/0016-7037(94)00287-V
M3 - Article
AN - SCOPUS:0000691835
SN - 0016-7037
VL - 59
SP - 475
EP - 479
JO - Geochimica et Cosmochimica Acta
JF - Geochimica et Cosmochimica Acta
IS - 3
ER -