Presentation Information
[P2-58]Crystal structure and Magnetic properties of Yb2Fe17 and Yb2Fe17Nx
*Tao Zhu1, Qiang Gao1,2, Jinbo Yang1,2 (1. State Key Laboratory for Mesoscopic Physics and School of Physics, Peking University (China), 2. Institute of Condensed Matter and Material Physics, School of Physics, Peking University (China))
Keywords:
Reduction-diffusion,Yb2Fe17,Negative thermal expansion,Yb2Fe17Nx,Neutron diffraction
In this study, high-purity rare-earth iron compound Yb2Fe17 was successfully synthesized via the reduction-diffusion method and subsequently transformed into Yb2Fe17Nx through a controlled nitridation process. X-ray diffraction (XRD) analysis revealed that both compounds crystallize in the Th2Ni17-type hexagonal structure (space group P63/mmc). The nitridation process induced significant lattice expansion, with an increase of 1.8% along the a-axis, 2.5% along the c-axis, and a total volume expansion (ΔV/V) of 6.2%. The intrinsic magnetic properties of both materials were systematically investigated. Yb2Fe17 exhibited typical ferromagnetic behavior at room temperature, with a saturation magnetization (MS) of 93.6 emu/g and a Curie temperature (TC) of 350 K. In contrast, the Yb2Fe17Nx demonstrated enhanced magnetic properties, with MS increasing to 143.2 emu/g and TC rising to 673 K. Thermal expansion behavior was examined via temperature-dependent neutron diffraction. Yb2Fe17 displayed anisotropic negative thermal expansion (NTE) between 4–400 K, whereas Yb2Fe17Nx exhibited anisotropic thermal expansion (PTE). This anomalous behavior is closely related to local lattice distortions induced by nitrogen incorporation. This study demonstrates that nitridation enables synergistic control over both magnetic properties and thermal expansion behavior in Yb2Fe17. The findings elucidate the coupling mechanism between lattice vibrations and magnetic interactions, providing critical insights for designing novel functional materials with tunable magnetic properties and low thermal expansion characteristics.