### Abstract

A polycrystalline sample of Fe _{2}GeMo _{3}N has been synthesized by the reductive nitridation of a mixture of binary oxides in a flow of 10% dihydrogen in dinitrogen. The reaction product has been studied by magnetometry, neutron diffraction and Mössbauer spectroscopy over the temperature range 1.8 ≤ T/K ≤ 700. The electronic structure and magnetic coupling have been modelled by Density Functional Theory (DFT) and Monte Carlo methods. Fe _{2}GeMo _{3}N adopts the cubic η-carbide structure with a = 11.1630(1) Å at 300 K. The electrical resistivity was found to be ∼0.9 mΩ cm over the temperature range 80 ≤ T/K ≤ 300. On cooling below 455 K the compound undergoes a transition from a paramagnetic to an antiferromagnetic state. The magnetic unit cell contains an antiferromagnetic arrangement of eight ferromagnetic Fe _{4} tetrahedra; the ordered atomic magnetic moments, 1.90(4) μ _{B} per Fe atom at 1.8 K, align along a <111> direction. DFT predicts an ordered moment of 1.831 μ _{B} per Fe. A random phase approximation to the DFT parameterised Heisenberg model yields a Néel temperature of 549 K, whereas the value of 431 K is obtained in the classical limit for spin. Monte Carlo calculations confirm that the experimentally determined magnetic structure is the lowest-energy antiferromagnetic structure, but with a lower Néel temperature of 412 K. These results emphasise the potential of these computational methods in the search for new magnetic materials.

Original language | English |
---|---|

Pages (from-to) | 15606-15613 |

Number of pages | 8 |

Journal | Journal of Materials Chemistry |

Volume | 22 |

Issue number | 31 |

DOIs | |

Publication status | Published - 2012 Aug 21 |

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### All Science Journal Classification (ASJC) codes

- Chemistry(all)
- Materials Chemistry

### Cite this

_{2}GeMo

_{3}N; An experimental and computational study.

*Journal of Materials Chemistry*,

*22*(31), 15606-15613. https://doi.org/10.1039/c2jm32574h

}

_{2}GeMo

_{3}N; An experimental and computational study',

*Journal of Materials Chemistry*, vol. 22, no. 31, pp. 15606-15613. https://doi.org/10.1039/c2jm32574h

**Magnetic properties of Fe _{2}GeMo _{3}N; An experimental and computational study.** / Battle, Peter D.; Sviridov, Lev A.; Woolley, Russell J.; Grandjean, Fernande; Long, Gary J.; Catlow, C. Richard A.; Sokol, Alexey A.; Walsh, Aron; Woodley, Scott M.

Research output: Contribution to journal › Article

TY - JOUR

T1 - Magnetic properties of Fe 2GeMo 3N; An experimental and computational study

AU - Battle, Peter D.

AU - Sviridov, Lev A.

AU - Woolley, Russell J.

AU - Grandjean, Fernande

AU - Long, Gary J.

AU - Catlow, C. Richard A.

AU - Sokol, Alexey A.

AU - Walsh, Aron

AU - Woodley, Scott M.

PY - 2012/8/21

Y1 - 2012/8/21

N2 - A polycrystalline sample of Fe 2GeMo 3N has been synthesized by the reductive nitridation of a mixture of binary oxides in a flow of 10% dihydrogen in dinitrogen. The reaction product has been studied by magnetometry, neutron diffraction and Mössbauer spectroscopy over the temperature range 1.8 ≤ T/K ≤ 700. The electronic structure and magnetic coupling have been modelled by Density Functional Theory (DFT) and Monte Carlo methods. Fe 2GeMo 3N adopts the cubic η-carbide structure with a = 11.1630(1) Å at 300 K. The electrical resistivity was found to be ∼0.9 mΩ cm over the temperature range 80 ≤ T/K ≤ 300. On cooling below 455 K the compound undergoes a transition from a paramagnetic to an antiferromagnetic state. The magnetic unit cell contains an antiferromagnetic arrangement of eight ferromagnetic Fe 4 tetrahedra; the ordered atomic magnetic moments, 1.90(4) μ B per Fe atom at 1.8 K, align along a <111> direction. DFT predicts an ordered moment of 1.831 μ B per Fe. A random phase approximation to the DFT parameterised Heisenberg model yields a Néel temperature of 549 K, whereas the value of 431 K is obtained in the classical limit for spin. Monte Carlo calculations confirm that the experimentally determined magnetic structure is the lowest-energy antiferromagnetic structure, but with a lower Néel temperature of 412 K. These results emphasise the potential of these computational methods in the search for new magnetic materials.

AB - A polycrystalline sample of Fe 2GeMo 3N has been synthesized by the reductive nitridation of a mixture of binary oxides in a flow of 10% dihydrogen in dinitrogen. The reaction product has been studied by magnetometry, neutron diffraction and Mössbauer spectroscopy over the temperature range 1.8 ≤ T/K ≤ 700. The electronic structure and magnetic coupling have been modelled by Density Functional Theory (DFT) and Monte Carlo methods. Fe 2GeMo 3N adopts the cubic η-carbide structure with a = 11.1630(1) Å at 300 K. The electrical resistivity was found to be ∼0.9 mΩ cm over the temperature range 80 ≤ T/K ≤ 300. On cooling below 455 K the compound undergoes a transition from a paramagnetic to an antiferromagnetic state. The magnetic unit cell contains an antiferromagnetic arrangement of eight ferromagnetic Fe 4 tetrahedra; the ordered atomic magnetic moments, 1.90(4) μ B per Fe atom at 1.8 K, align along a <111> direction. DFT predicts an ordered moment of 1.831 μ B per Fe. A random phase approximation to the DFT parameterised Heisenberg model yields a Néel temperature of 549 K, whereas the value of 431 K is obtained in the classical limit for spin. Monte Carlo calculations confirm that the experimentally determined magnetic structure is the lowest-energy antiferromagnetic structure, but with a lower Néel temperature of 412 K. These results emphasise the potential of these computational methods in the search for new magnetic materials.

UR - http://www.scopus.com/inward/record.url?scp=84863906127&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84863906127&partnerID=8YFLogxK

U2 - 10.1039/c2jm32574h

DO - 10.1039/c2jm32574h

M3 - Article

AN - SCOPUS:84863906127

VL - 22

SP - 15606

EP - 15613

JO - Journal of Materials Chemistry

JF - Journal of Materials Chemistry

SN - 0959-9428

IS - 31

ER -

_{2}GeMo

_{3}N; An experimental and computational study. Journal of Materials Chemistry. 2012 Aug 21;22(31):15606-15613. https://doi.org/10.1039/c2jm32574h