Oxygen diffusion in Bi2O3-doped ZnO

• Published in: Materials research (São Carlos, São Paulo, Brazil) Vol. 11; no. 2; pp. 221 - 225
• Main Authors: Sabioni, Antônio Claret Soares, Daniel, Antônio Márcio J.M., Ferraz, Wilmar Barbosa, Pais, Rafael Witter Dias, Huntz, Anne-Marie, Jomard, François
• Format: Journal Article
• Language: English
• Published: ABM, ABC, ABPol 01-06-2008; Associação Brasileira de Metalurgia e Materiais (ABM); Associação Brasileira de Cerâmica (ABC); Associação Brasileira de Polímeros (ABPol)
• Subjects: Bi2O3-doped ZnO; bulk diffusion; ENGINEERING, CHEMICAL; grain boundary diffusion; MATERIALS SCIENCE, MULTIDISCIPLINARY; METALLURGY & METALLURGICAL ENGINEERING; oxygen diffusion; oxygen diffusion; bulk diffusion; Bi2O3-doped ZnO; grain boundary diffusion
• ISSN: 1516-1439; 1980-5373; 1516-1439
• DOI: 10.1590/S1516-14392008000200019

In order to clarify the influence of Bi-doping on oxygen diffusion in ZnO, the bulk and grain boundary oxygen diffusion coefficients were measured in Bi2O3-doped ZnO polycrystals by means of the gas-solid exchange method using the isotope 18O as the oxygen tracer. The experiments were performed on ZnO sintered samples containing 0.,0.3 and 0.5 mol% Bi2O3. The diffusion annealings were performed at 942, 1000 and 1092 C, in an Ar+18O2 atmosphere under an oxygen partial pressure of 0.2 atm. After the diffusion annealings, the 18O diffusion profiles were established by SIMS. The results showed an increase in oxygen diffusion in the Bi2O3-doped ZnO, when compared to oxygen diffusion in the undoped ZnO polycrystal under the same experimental conditions, both in bulk and in grain-boundaries. It was observed that the higher the Bi2O3 concentration, the higher the oxygen diffusion. These results suggest that the incorporation of Bi2O3 increases the interstitial oxygen concentration which agrees with an interstitial diffusion mechanism both in bulk and in grain-boundaries. 10 refs.