By a News Reporter-Staff News Editor at Life Science Weekly -- Investigators publish new report on Chalcogens. According to news reporting from Roskilde, Denmark, by NewsRx journalists, research stated, "The densification and grain growth of the solid state ionic conductor material Ce0.9Gd0.10O1.95-delta, (i.e. GDC10, gadolinium-doped ceria, with Gd 10 mol.%) are analysed for nanometric and fine powders of various particle sizes, both in air and in a 9 vol.% H-2-N-2 mixture."
The news correspondents obtained a quote from the research from the Technical University of Denmark, "Due to a dominant solute drag effect in aliovalent highly doped ceria, the starting morphology of the powders controls the diffusion mechanisms of the material in air. Conversely, highly enhanced densification and grain growth are achieved by firing the materials at reduced temperatures (800 < T< 1200 degrees C) in low oxygen activity atmospheres (pO(2) < 10(-1)2 atm). Solute drag is not the rate-limiting step in highly defective GDC and the densification mechanisms are nearly independent of the starting powder properties. Fast diffusion is activated under low oxygen activity with high grain boundary mobility (e.g. M-gb similar to 10(-10) m(3) N-1 s(-1) at 1100 degrees C). The change of the dominant sintering mechanisms under low oxygen activity is attributed to the formation of a large concentration of oxygen vacancies (Vo), electronic defects (Ce'(Ce), i.e. Ce3+) and reduced Gd/Ce cation mismatch."
According to the news reporters, the research concluded: "High densification and electric conductivity are achieved in Ce0.9Gd0.1O1.95-delta at low temperatures (similar to 1000 degrees C) and low oxygen activity, preserving the mechanical integrity of the material."
For more information on this research see: Enhanced mass diffusion phenomena in highly defective doped ceria. Acta Materialia, 2013;61(16):6290-6300. Acta Materialia can be contacted at: Pergamon-Elsevier Science Ltd, The Boulevard, Langford Lane, Kidlington, Oxford OX5 1GB, England. (Elsevier - www.elsevier.com; Acta Materialia - www.elsevier.com/wps/product/cws_home/221)
Our news journalists report that additional information may be obtained by contacting V. Esposito, Technical University of Denmark, Dept. of Energy Convers & Storage, DK-4000 Roskilde, Denmark. Additional authors for this research include D. Ni, Z.M. He, W. Zhang, A.S. Prasad, J.A. Glasscock, C. Chatzichristodoulou, S. Ramousse and A. Kaiser (see also Chalcogens).
Keywords for this news article include: Europe, Denmark, Roskilde, Chalcogens
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