Unraveling the magnetic structure of YbNiSn single crystal via crystal growth and neutron diffraction

• Published in: Journal of magnetism and magnetic materials 2023-10, Vol.584, p.171054, Article 171054
• Main Authors: Wu, H.C., Nakamura, A., Okuyama, D., Nawa, K., Aoki, D., Sato, T.J.
• Format: Article
• Language: English
• ISSN: 0304-8853
• DOI: 10.1016/j.jmmm.2023.171054

•High-quality single crystals of YbNiSn with the residual resistivity ratio (RRR) of 55–80 were grown using the Bridgman method.•We report the magnetic structure determination of the ternary intermetallic compound YbNiSn through single crystal neutron diffraction experiments.•Our findings reveal an antiferromagnetic-type magnetic structure, in contrast to the previously proposed collinear ferromagnetic structure.•We have observed a spin-flop transition under 1 T along the a axis, resulting in a change in the magnetic space group from Pn'm'a to Pnm'a'. Neutron and X-ray diffraction experiments were performed on the ternary intermetallic compound YbNiSn, formerly categorized as a ferromagnetic Kondo compound. At zero field, an increase in scattering intensity was observed on top of allowed and forbidden nuclear reflections below Tc, breaking the reflection condition of the crystal symmetry Pnma. This indicates that the magnetic structure of YbNiSn is antiferromagnetic-type, rather than the previously proposed simple collinear ferromagnetic structure. Temperature dependence of the scattering intensity of the 011 reflection confirmed the magnetic ordering at 5.77(2) K. No incommensurate satellite reflection was observed at 2.5 K. By applying external magnetic field of 1 T along the a axis, the magnetic intensity at the nuclear-forbidden 001 position was suppressed, while a slight enhancement at the nuclear-allowed 002 position was observed. This suggests a spin-flip transition under the external magnetic field along the a axis in YbNiSn. The proposed magnetic structures at zero field and 1 T correspond to the magnetic space groups of Pn'm'a and Pnm'a', respectively. The piezomagnetic effect and the switch between the two magnetic space groups by the external stress, which could be detected by the anomalous Hall effect, are proposed.