Effect of carbon on interstitial ordering and magnetic properties of epsilon-Fe-2(N,C)(1-z)

0473572 - ÚJF 2018 RIV CH eng J - Článek v odborném periodiku
Brink, B. K. - Stahl, K. - Christiansen, T. L. - Frandsen, C. - Hansen, M. F. - Beran, Přemysl - Somers, M. A. J.
Effect of carbon on interstitial ordering and magnetic properties of epsilon-Fe-2(N,C)(1-z).
Journal of Alloys and Compounds. Roč. 694, FEB (2017), s. 282-291. ISSN 0925-8388. E-ISSN 1873-4669
Grant CEP: GA MŠMT LM2015056
Institucionální podpora: RVO:61389005
Klíčová slova: neutron diffraction * vibrating sample magnotometry * Epsilon iron nitride * thermal expansion * interstitial order
Obor OECD: Condensed matter physics (including formerly solid state physics, supercond.)
Impakt faktor: 3.779, rok: 2017

Hexagonal epsilon-iron nitride and e-iron carbonitride phases are formed on nitriding and nitrocarburizing of iron and steel surfaces and can exist in broad compositional ranges. Long-range nitrogen ordering and magnetic properties for epsilon-iron nitrides and their dependence on composition have been the focus of several studies. So far, limited attention has been paid to the carbonitrides. In the current work, the effects of substitution of nitrogen by carbon on the interstitial ordering and magnetic properties in Fe-2(C,N)(1-z) are explored using neutron diffraction, Mossbauer spectroscopy and vibrating sample magnetometry. Neutron diffraction patterns showed 001 and 301 superstructure reflections, confirming a previously proposed structural model in space group P (3) over bar1 m (compared to P6(3)22 for the pure nitrides). On partial substitution of nitrogen by carbon in epsilon-iron nitride the Curie temperature, the saturation magnetization and the hyperfine fields of the iron atoms are increased, while isomer shifts are decreased. The effects on the a and c lattice parameters indicate a change in interstitial ordering, which is related to more favorable interactions between a nitrogen and carbon atom than among nitrogen atoms. This interaction leads to additional interstitial (short-range) ordering and a decrease in the c lattice parameter, while the a lattice parameter is largely unaffected.
Trvalý link: http://hdl.handle.net/11104/0270703