Y2Co3 is a newly discovered antiferromagnetic (AFM) compound with distorted kagome layers. Previous investigations via bulk magnetization measurements suggested a complex noncollinear magnetic behavior, with magnetic moments primarily anti-aligned along the b axis and some canting towards the ac plane. In this study, we report the magnetic structure of Y2Co3 to be an A-type AFM structure with ferromagnetic (FM) interactions within the distorted kagome plane and an interplane antiferromagnetic interaction, as determined by single-crystal neutron diffraction. The magnetic moments align along the b axis, with minimal canting towards the c axis, at odds with the previous interpretation of bulk magnetization measurements. The magnetic moments on the two distinct Co sites are [0, -0.68(3), 0] μB and [0, 1.25(4), 0.07(1)] μB. We attribute the previously reported "noncollinear" behavior to the considerable temperature dependence of itinerant AFM exchange interactions, induced by thermal contraction along the b axis. Additionally, our examination of lattice constants through pressure studies reveals compensating effects on FM and AFM interactions, resulting in negligible pressure dependence of TN.
@article{arxiv.2501.15706,
title = {Anomalous temperature-dependent magnetization in the nearly collinear antiferromagnet Y$_2$Co$_3$},
author = {Yunshu Shi and Huibo Cao and Hung-Cheng Wu and Li Yin and Neil Harrison and David S. Parker and Tushar Bhowmick and Tessa McNamee and Fatemeh Safari and Sergey L. Budko and James C. Fettinger and Susan M. Kauzlarich and Peter Klavins and Dmitry Popov and Ravhi Kumar and Russell J. Hemley and Shanti Deemyad and Taku J. Sato and Paul. C. Canfield and Valentin Taufour},
journal= {arXiv preprint arXiv:2501.15706},
year = {2025}
}