ELECTRONIC-PROPERTIES AND DEFECT STRUCTURE OF FE AND FE-CR PASSIVE FILMS

被引：32

作者：

KLOPPERS, MJ ^{[1
]}

BELLUCCI, F ^{[1
]}

LATANISION, RM ^{[1
]}

机构：

[1] MIT,HH UHLIG CORROS LAB,CAMBRIDGE,MA 02139

来源：

CORROSION | 1992年 / 48卷 / 03期

关键词：

IMPEDANCE; PASSIVE FILM; PHOTOELECTROCHEMISTRY; POINT DEFECT; VACANCY;

D O I：

10.5006/1.3315929

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

The electronic properties of passive films on Fe-Cr alloys were determined by the photoelectrochemical technique. Measurement of the flat band potential for the passive films on the different alloys indicated that the film is doped increasingly n-type as the Cr concentration in the base alloy is increased This doping is due to a Cr oxide with Cr in the 4+ or 6+ valence state. The concentration of this doping species increases as the concentration of Cr in the Fe-Cr alloy is increased. The n-type doping has the effect of decreasing the number of oxygen vacancies in the Fe-Cr passive film. Since oxygen vacancies are the mobile point defect species in the Fe-Cr passive film, decreasing this species decreases the oxygen vacancy flux and ultimately the passive film growth kinetics. The contribution of film dissolution and cation transmission through the passive film was also analyzed Film dissolution was shown to be the major contribution to the passive current density.

引用

页码：229 / 238

页数：10

共 39 条

[1] ELECTRIC TRANSPORT IN N-TYPE FE2O3 [J].