Effect of oxygen partial pressure on the semiconducting properties of thermally grown chromia on pure chromium. (15th August 2018)

• Record Type: Journal Article
• Authors: Parsa, Y.; Latu-Romain, L.; Wouters, Y.; Mathieu, S.; Perez, T.; Vilasi, M.
• Is Part Of: Corrosion science. Volume 141(2018)
• Page Start: 46
• Page End: 52
• Publication Date: 2018-08-15
• Subjects: Photoelectrochemistry -- TEM -- Chromia -- High temperature oxidation; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2018.06.038
• Languages: English
• ISSNs: 0010-938X

Abstract

Highlights: Pure Cr has been oxidized in order to grow insulating chromia. Buffers have been fabricated to vary the p (O2 ) without changing the temperature. A chromia semiconducting properties diagram is proposed versus oxygen activity. The stoichiometric chromia layer appears to be more protective. Abstract: Oxidation of chromium at 800 °C for 30 min at oxygen activity from 5.10 −14 atm to 5.10 −13 atm have been conducted to grow an insulating chromia. Microstructural and semiconducting properties have been investigated using electron microscopy and photoelectrochemistry. The scales always exhibit a duplex microstructure with equiaxed and columnar grains, as well as a both n-type and insulating semiconduction type. Successive oxidation tests have demonstrated the higher protective nature of this chromia scale compared to the air grown one. Chromia semiconducting properties are finally described vs. oxygen activity in a large range of variation.