Oxygen diffusion in Bi2O3-doped ZnO

Antônio Claret Soares Sabioni, Antônio Márcio J.M. Daniel, Wilmar Barbosa Ferraz, Rafael Witter Dias Pais, Anne-Marie Huntz, François Jomard
2008 Materials Research  
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 Bi 2 O 3 -doped ZnO polycrystals by means of the gas-solid exchange method using the isotope 18 O as the oxygen tracer. The experiments were performed on ZnO sintered samples containing 0.1, 0.3 and 0.5 mol% Bi 2 O 3 . The diffusion annealings were performed at 942, 1000 and 1092 °C, in an Ar+ 18 O 2 atmosphere under an oxygen partial pressure of
more » ... artial pressure of 0.2 atm. After the diffusion annealings, the 18 O diffusion profiles were established by secondary ion mass spectrometry (SIMS). The results show an increase in the oxygen diffusion in the Bi 2 O 3 -doped ZnO, when compared to the oxygen diffusion in the undoped ZnO polycrystal under the same experimental conditions, both in bulk and in grain-boundaries. Moreover, it was observed that the higher the Bi 2 O 3 concentration, the higher the oxygen diffusion. These results suggest that the incorporation of Bi 2 O 3 increases the interstitial oxygen concentration which agrees with an interstitial diffusion mechanism both in bulk and in grain-boundaries.
doi:10.1590/s1516-14392008000200019 fatcat:qh2uypq435cqdmq6fvd7ouatzq