Nonstoichiometry and defect structures in copper oxides and ferrites

• Published in: Journal of solid state chemistry Vol. 5; no. 2; pp. 157 - 167
• Main Authors: Tretyakov, Yu.D., Komarov, V.F., Prosvirnina, N.A., Kutsenok, I.B.
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.01.1972
• ISSN: 0022-4596; 1095-726X
• DOI: 10.1016/0022-4596(72)90024-2

The stoichiometry ranges of Cu 2O 1 + γ, CuO 1 + γ, Cu 0.984Fe 2.016O 4 + γ, Cu 1.011Fe 1.989O 4 + γ, and Cu 0.551Fe 2.449O 4 + γ were established by high temperature electrochemical measurements in a stabilized zirconia electrolyte cell. The results were consistent with neutral oxygen vacancies for oxygen deficit and neutral cation vacancies for oxygen excess in cuprite, neutral oxygen vacancies in Cu 1.011Fe 1.989O 4 + γ and Cu 0.551Fe 2.449O 4 + γ, neutral cation vacancies in Cu 0.984Fe 2.016O 4 + γ and neutral associations of interstitial copper atoms in cupric oxide. The defect structures of these compounds were derived from the consideration of equilibrium with respect to oxygen between the solid and the gas phase. The absolute magnitudes of nonstoichiometry, defect concentrations and the enthalpy of defect formation were calculated. The enthalpies of the formation of Schottky defects in “Cu 2O” and “CuFe 2O 4” were calculated.