T. Wakia, 
, 
, S. Terazawaa, Y. Tabataa, Y. Muraseb, M. Katob, K. Hirotab, S. Ikedac, H. Kobayashic, K. Satod, 1, K. Kindod, H. Nakamuraa
| a | Department of Materials Science and Engineering, Kyoto University, Kyoto 606-8501, Japan |
| b | Department of Molecular Chemistry and Biochemistry, Faculty of Science and Engineering, Doshisha University, Kyo-Tanabe 610-0321, Japan |
| c | Graduate School of Material Science, University of Hyogo, Kamigori, Hyogo 678-1297, Japan |
| d | The Institute for Solid State Physics, The University of Tokyo, Kashiwa 277-8581, Japan |
Received 9 May 2011; revised 7 July 2011; Accepted 8 July 2011. Available online 20 July 2011.
Abstract
We have succeeded in synthesising iron–tungsten nitrides using the hot isostatic pressing (HIP) method and have measured their magnetic properties. Two η-carbide-type iron–tungsten nitrides with lattice constants a = 11.043(1) and 10.937(2) Å were synthesised directly from metal elements under high-pressure nitrogen gas. Their compositions are expected to be Fe3W3N and Fe6W6N in analogy with other η-carbide-type compounds. Fe3W3N is a ferromagnet with a Curie temperature TC = 110 K and a saturation moment PS = 0.78μB/Fe, whereas Fe6W6N is an antiferromagnet with a Néel temperature TN = 75 K and shows a metamagnetic transition at around 25 T.
