Competing redox reactions in Fe-containing AlO(OH) and Al₂O ₃ matrices

A combined investigation by Mössbauer, ESR spectroscopy and thermal analysis

authored by

R. Stößer, M. Menzel, M. Feist, M. Nofz, F. Renz

Abstract

The investigation of iron-doped AlO(OH)/Al₂O₃ systems revealed that the combined employment of Mössbauer and ESR spectroscopies together with thermal analysis yields meaningful data with complementary information. This mutual complementarity is based on the coexistence of Fe point defects with the corresponding aggregated FeO_x species which has been observed even for very low Fe concentrations. Competing redox processes between the dopant, the AlO_x matrix, and the gas atmosphere during the thermal treatment enable the generation of solid phases exhibiting specific chemical properties. The entire reaction process is influenced by a specific mechanical and thermal pre-treatment that affects predominantly oxydative processes in the matrix. A protecting influence of the matrix preventing further reductive attack of the Fe³⁺ Fe²⁺ ions by hydrogen has been established.

Organisation(s)

Institute of Inorganic Chemistry

External Organisation(s)

Humboldt-Universität zu Berlin (HU Berlin)
BAM Federal Institute for Materials Research and Testing

Type

Conference article

Journal

Journal of Physics: Conference Series

Volume

217

ISSN

1742-6588

Publication date

2010

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

General Physics and Astronomy

Electronic version(s)

https://doi.org/10.1088/1742-6596/217/1/012028 (Access: Open)