Duplex n- and p-Type Chromia Grown on Pure Chromium: A Photoelectrochemical and Microscopic Study

详细信息    查看全文

• 作者：L. Latu-Romain ; Y. Parsa ; S. Mathieu ; M. Vilasi ; M. Ollivier…
• 关键词：Chromia ; Photoelectrochemistry ; TEM characterizations ; Point defects
• 刊名：Oxidation of Metals
• 出版年：2016
• 出版时间：December 2016
• 年：2016
• 卷：86
• 期：5-6
• 页码：497-509
• 全文大小：1,363 KB
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Chemistry
  Inorganic Chemistry
  Tribology, Corrosion and Coatings
  Metallic Materials
  
• 出版者：Springer Netherlands
• ISSN：1573-4889
• 卷排序：86

文摘

Chromia grown on pure chromium at 900 °C for 30 min at an oxygen partial pressure p(O₂) of 10−12 atm has been characterized using photoelectrochemical and electron microscopy techniques. This study reveals a duplex scale: n-chromia with equiaxis morphology in the internal part (~650 nm thick) and p-chromia with columnar morphology in the external part (~900 nm thick). Grain orientation maps also revealed the presence of a c-oriented chromia layer at the interface between the n- and the p-subscales. This 〈 0001 〉 textured layer was identified as the first-grown chromia layer. It means that internal n-equiaxis chromia grew by anionic transport governed by oxygen vacancy diffusion, whereas external p-columnar chromia layer grew outwards and was controlled by chromium vacancy diffusion.