Abstract
The Gibbs' energies of formation of BaCuO2, Y2Cu2O5 and Y2BaCuO5 from component oxides have been measured using solid state galvanic cells incorporating CaF2 as the solid electrolyte under pure oxygen at a pressure of 1.01×105 Pa 〈BaO〉 + 〈CuO〉 → 〈BaCuO2〉 ΔG of,ox (± 0.3) (kJ mol−1)=−63.4−0.0525T(K) 〈Y2O3〉 + 2〈CuO〉 → 〈Y2Cu2O2〉 ΔG of,ox (± 0.3) (kJ mol−1)=18.47−0.0219T(K) 〈Y2O3〉 + 〈BaO〉 + 〈CuO〉 → 〈Y2BaCuO5〉 ΔG of,ox (± 0.7) (kJ mol−1)=−72.5−0.0793T(K) Because the superconducting compound YBa2Cu3O7−δ coexists with any two of the phases CuO, BaCuO2 and Y2BaCuO5, the data on BaCuO2 and Y2BaCuO5 obtained in this study provide the basis for the evaluation of the Gibbs' energy of formation of the 1-2-3 compound at high temperatures.
Similar content being viewed by others
References
M. K. Wu, J. R. Ashburn, C. J. Torng, P. H. Hor, R. L. Meng, L. Gao, Z. J. Huang, Y. Q. Wang andC. W. Chu,Phys. Rev. Lett. 58 (1987) 908.
G. M. Kale andK. T. Jacob,Solid State Ionics. 34 (1989) 247.
Idem., Mater. Chem. 1 (1989) 515.
R. Pankajavalli andO. M. Sreedharan,J. Mater. Sci. Lett. 7 (1988) 714.
A. M. Azad andO. M. Sreedharan,ibid. 8 (1989) 67.
R. Pankajavalli andO. M. Sreedharan,ibid. 8 (1989) 225.
Idem., ibid. 8 (1989) 697.
F. Toci, A. Schruenkamper, M. Cambini andL. Manes,Phys. C 153/155 (1988) 838.
J. L. MacManus, D. J. Fray andJ. E. Evetts,Supercond. Sci. Technol. 1 (1989) 291.
K. G. Frase, E. G. Liniger andD. A. Clarke,J. Amer. Ceram. Soc. 70 (1987) C 204.
K. G. Frase andD. A. Clarke,Adv. Ceram. Mater. 2 (3B) (1987) 295 (special issue).
G. Wang, S.-J. Wu, S. N. Song, J. B. Ketterson, L. D. Marks, K. R. Poeppelmeier andT. D. Mason,ibid. 2 (3B) (1987) 313.
R. S. Roth, K. L. Davis andJ. R. Dennis,ibid. 2 (3B) (1987) 303.
D. M. De Leeuw, C. A. H. A. Mutsaers, C. Langeries, H. C. A. Smoorenburg andP. J. Rommers,Phys. C 152 (1988) 39.
K. T. Jacob andY. Waseda, private communication.
Yu. D. Tretyakov, A. R. Kaul andN. V. Makukhin,J. Solid State Chem. 17 (1976) 183.
A. M. Azad andO. M. Sreedharan,J. Appl. Electrochem. 17 (1987) 949.
V. A. Levitskii,J. Solid State Chem. 25 (1978) 9.
G. H. Rao, J. K. Liang andZ. Y. Qiao,J. Less-Common Metals 144 (1988) 215.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Azad, A.M., Sreedharan, O.M. & Jacob, K.T. Standard Gibbs' energies of formation of BaCuO2, Y2Cu2O5 and Y2BaCuO5 . J Mater Sci 26, 3374–3379 (1991). https://doi.org/10.1007/BF01124688
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/BF01124688