Effect of carbon on interstitial ordering and magnetic properties of ε-Fe2(N,C)1-z

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Abstract

Hexagonal ε-iron nitride and ε-iron carbonitride phases are formed on nitriding and nitrocarburizing ofiron and steel surfaces and can exist in broad compositional ranges. Long-range nitrogen ordering andmagnetic properties for ε-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 Fe2(C,N)1-z are explored using neutron diffraction, M€ossbauer spectroscopy and vibrating samplemagnetometry. Neutron diffraction patterns showed 001 and 301 superstructure reflections, confirminga previously proposed structural model in space group P31m (compared to P6322 for the pure nitrides).On partial substitution of nitrogen by carbon in ε-iron nitride the Curie temperature, the saturationmagnetization 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 tomore favorable interactions between a nitrogen and carbon atom than among nitrogen atoms. Thisinteraction leads to additional interstitial (short-range) ordering and a decrease in the c lattice parameter,while the a lattice parameter is largely unaffected.
Original languageEnglish
JournalJournal of Alloys and Compounds
Volume694
Pages (from-to)282-291
ISSN0925-8388
DOIs
Publication statusPublished - 2017

Keywords

  • Neutron diffraction
  • Vibrating sample magnetometry
  • Epsilon iron nitride
  • Thermal expansion
  • Interstitial order

Cite this

@article{ea6cd5041d8d4deba203302157786633,
title = "Effect of carbon on interstitial ordering and magnetic properties of ε-Fe2(N,C)1-z",
abstract = "Hexagonal ε-iron nitride and ε-iron carbonitride phases are formed on nitriding and nitrocarburizing ofiron and steel surfaces and can exist in broad compositional ranges. Long-range nitrogen ordering andmagnetic properties for ε-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 Fe2(C,N)1-z are explored using neutron diffraction, M€ossbauer spectroscopy and vibrating samplemagnetometry. Neutron diffraction patterns showed 001 and 301 superstructure reflections, confirminga previously proposed structural model in space group P31m (compared to P6322 for the pure nitrides).On partial substitution of nitrogen by carbon in ε-iron nitride the Curie temperature, the saturationmagnetization 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 tomore favorable interactions between a nitrogen and carbon atom than among nitrogen atoms. Thisinteraction leads to additional interstitial (short-range) ordering and a decrease in the c lattice parameter,while the a lattice parameter is largely unaffected.",
keywords = "Neutron diffraction, Vibrating sample magnetometry, Epsilon iron nitride, Thermal expansion, Interstitial order",
author = "Bastian Brink and Kenny St{\aa}hl and Christiansen, {Thomas Lundin} and Cathrine Frandsen and Hansen, {Mikkel Fougt} and Přemysl Beran and Somers, {Marcel A. J.}",
year = "2017",
doi = "10.1016/j.jallcom.2016.09.317",
language = "English",
volume = "694",
pages = "282--291",
journal = "Journal of Alloys and Compounds",
issn = "0925-8388",
publisher = "Elsevier",

}

Effect of carbon on interstitial ordering and magnetic properties of ε-Fe2(N,C)1-z. / Brink, Bastian; Ståhl, Kenny; Christiansen, Thomas Lundin; Frandsen, Cathrine; Hansen, Mikkel Fougt; Beran, Přemysl; Somers, Marcel A. J.

In: Journal of Alloys and Compounds, Vol. 694, 2017, p. 282-291.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Effect of carbon on interstitial ordering and magnetic properties of ε-Fe2(N,C)1-z

AU - Brink, Bastian

AU - Ståhl, Kenny

AU - Christiansen, Thomas Lundin

AU - Frandsen, Cathrine

AU - Hansen, Mikkel Fougt

AU - Beran, Přemysl

AU - Somers, Marcel A. J.

PY - 2017

Y1 - 2017

N2 - Hexagonal ε-iron nitride and ε-iron carbonitride phases are formed on nitriding and nitrocarburizing ofiron and steel surfaces and can exist in broad compositional ranges. Long-range nitrogen ordering andmagnetic properties for ε-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 Fe2(C,N)1-z are explored using neutron diffraction, M€ossbauer spectroscopy and vibrating samplemagnetometry. Neutron diffraction patterns showed 001 and 301 superstructure reflections, confirminga previously proposed structural model in space group P31m (compared to P6322 for the pure nitrides).On partial substitution of nitrogen by carbon in ε-iron nitride the Curie temperature, the saturationmagnetization 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 tomore favorable interactions between a nitrogen and carbon atom than among nitrogen atoms. Thisinteraction leads to additional interstitial (short-range) ordering and a decrease in the c lattice parameter,while the a lattice parameter is largely unaffected.

AB - Hexagonal ε-iron nitride and ε-iron carbonitride phases are formed on nitriding and nitrocarburizing ofiron and steel surfaces and can exist in broad compositional ranges. Long-range nitrogen ordering andmagnetic properties for ε-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 Fe2(C,N)1-z are explored using neutron diffraction, M€ossbauer spectroscopy and vibrating samplemagnetometry. Neutron diffraction patterns showed 001 and 301 superstructure reflections, confirminga previously proposed structural model in space group P31m (compared to P6322 for the pure nitrides).On partial substitution of nitrogen by carbon in ε-iron nitride the Curie temperature, the saturationmagnetization 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 tomore favorable interactions between a nitrogen and carbon atom than among nitrogen atoms. Thisinteraction leads to additional interstitial (short-range) ordering and a decrease in the c lattice parameter,while the a lattice parameter is largely unaffected.

KW - Neutron diffraction

KW - Vibrating sample magnetometry

KW - Epsilon iron nitride

KW - Thermal expansion

KW - Interstitial order

U2 - 10.1016/j.jallcom.2016.09.317

DO - 10.1016/j.jallcom.2016.09.317

M3 - Journal article

VL - 694

SP - 282

EP - 291

JO - Journal of Alloys and Compounds

JF - Journal of Alloys and Compounds

SN - 0925-8388

ER -