Re-examination of the non-stoichiometry and defect structure of copper(II)oxide or tenorite, Cu1 +/- zO or CuO1 +/-epsilon - A short review

Four sets of compositional data with a departure z or epsilon from the stoi chiometry of tenorite Cu1+/-zO or CuO1+/-epsilon are re-examined for possib le point defects. Correlations z(p(O2)) at equilibrium solid double left ri ght arrow pure di-oxygen - when they can be computed - indicate the presenc e of either oxygen vacancies or copper interstitials or clusters of them. S ome recent data after quenching are in favor of copper interstitials. Few d ata concerning tenorite prepared by decomposition of a salt, by oxidation o f copper and by CVT in sealed tubes have generally been interpreted in the literature as indicating copper deficiency. In those oxides a large departu re from the stoichiometry indicates a complex behavior likely due to severa l point defects possibly ordering at short and/or long range, and including chemical impurities in the case of sealed tube preparation. It is, however , in fact likely that the defect structure of such samples involves the two sub-lattices. Cu3O2- or Cu4O3-like clusters can even be envisaged. (C) 199 9 Elsevier Science B.V. All rights reserved.