We have successfully synthesized single crystals of the site-ordered cubic (C15b) Laves phase compound LuInCo4 with the Co-pyrochlore sublattice for the first time. LuInCo4 undergoes a ferromagnetic transition at 306 K and has a saturation moment of 3.43 μB/f.u. at 5 K. The strongly ferromagnetic nature was verified by DFT calculations, suggesting that Co-3d flat bands near the Fermi level induce the spin polarization. The magnetization is isotropic above ∼100 K, saturates most easily in the [100] direction at low temperatures. In this anisotropic ferromagnetic state, the magnetization undergoes a metamagnetic transition in the [111] direction. Our results suggest that LuInCo4 is a new strong but unusual itinerant electron ferromagnet, which deserves further study as a pyrochlore metal.
@article{arxiv.2408.12166,
title = {Unusual strong ferromagnetism in site-ordered cubic Laves phase compound LuInCo$_4$ with Co-pyrochlore lattice},
author = {Taiki Shiotani and Hiroto Ohta and Takeshi Waki and Yoshikazu Tabata and Hiroyuki Nakamura},
journal= {arXiv preprint arXiv:2408.12166},
year = {2024}
}