کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
181637 | 459406 | 2008 | 4 صفحه PDF | دانلود رایگان |
The local electrical conductivity and chemical composition of hyper-stoichiometric uranium dioxide were studied using localized Raman and current-sensing AFM techniques. Distinct types of surface features, representative of either stoichiometric or hyper-stoichiometric uranium dioxide, and remarkably different in their electrical conductivity, were identified. Stoichiometric UO2 formed smooth featureless grains and showed little or no electrical conductivity, while considerably more conducting hyper-stoichiometric UO2+x formed characteristic ridges and/or facetted structures. Surprisingly, such hyper-stoichiometric regions also showed anisotropic electrical conductivity and combined relatively non-conducting flat terraces with a highly conducting inclined facets. Our CS-AFM measurements clearly indicate that the highly conducting grain boundaries, as well as facetted grains and grain regions, are the prime locations for local corrosion.
Journal: Electrochemistry Communications - Volume 10, Issue 11, November 2008, Pages 1805–1808