Study of mechanically synthesized carbide Fe7C3

• Published in: Physics of metals and metallography Vol. 110; no. 5; pp. 474 - 484
• Main Authors: Barinov, V. A., Tsurin, V. A., Surikov, V. T.
• Format: Journal Article
• Language: English
• Published: Dordrecht SP MAIK Nauka/Interperiodica 01-11-2010
• Subjects: Boundaries; Carbides; Chemistry and Materials Science; Curie temperature; Diffusion; Interaction parameters; Iron; Magnetic properties; Materials Science; Mathematical analysis; Metallic Materials; Phase Transformations; Structure; Toluene; mechanical synthesis; iron carbides; phase transition; Mössbauer investigations; Curie temperature
• ISSN: 0031-918X; 1555-6190
• DOI: 10.1134/S0031918X10110074

Magnetic properties and hyperfine interactions in the carbide Fe
7
C
3
prepared by mechanical synthesis (MS) of α-Fe in toluene have been studied. It has been found that the boundary of temperature stability of the MS carbide does not exceed 775 K. The Curie temperature of the synthesized phase varies between 509 and 525 K. The Mössbauer experiments (
57
Fe) have demonstrated that the unit cell of Fe
7
C
3
contains 32 iron atoms distributed over five types of crystallographic positions with a multiplicity of 4: 8: 8: 8: 4. The hyperfine interaction parameters have been calculated for each nonequivalent position. It may be conjectured from the specific features of the decomposition at
T
≥ 775 K that the most probable sequence of the phase transitions in the MS carbides Fe-C is → θ, where -Adcock carbide Fe
7
C
3
.