Publication Date:
2004-01-17
Description:
The cementite phase of Fe3C has been studied by high-resolution neutron powder diffraction at 4.2 K and at 20 K intervals between 20 and 600 K. The crystal structure remains orthorhombic (Pnma) throughout, with the fractional coordinates of all atoms varying only slightly (the magnetic structure of the ferromagnetic phase could not be determined). The ferromagnetic phase transition, withTc≃ 480 K, greatly affects the thermal expansion coefficient of the material. The average volumetric coefficient of thermal expansion aboveTcwas found to be 4.1 (1) × 10−5 K−1; belowTcit is considerably lower (
Print ISSN:
0021-8898
Electronic ISSN:
1600-5767
Topics:
Geosciences
,
Physics
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