The crystal and magnetic structures of the nitride antiperovskite Mn3GeN reveals ferrimagnetic order stemming from a distorted kagome-derived lattice of the Mn atoms. Polycrystalline Mn3GeN was synthesized via a solid-state reaction and characterized using neutron powder diffraction, DC magnetometry, and first-principles calculations. Rietveld refinement reveals near-stoichiometric composition (Mn3GeN0.94(1)) adopting a tetragonal I4/mcm structure at T = 500 K and below, featuring axially distorted and tilted [NMn6] octahedra that result in a buckled Mn kagome lattice. On heating, the tetragonal distortion and octahedral tilt angle decrease continuously before transitioning to the cubic Pm3ˉm antiperovskite phase at T≈ 524 K. Neutron diffraction and magnetometry together reveal noncollinear ferrimagnetic ordering. For 30 K ≤T≤ 500 K, the magnetic structure is described by a single propagation vector, k = (0, 0, 0), with inequivalent Mn1 and Mn2 sublattices that couple antiferromagnetically to yield a net moment. Density functional theory-based calculations show the different local moments originate from the bandwidths associated with the distinct Mn-N bond lengths. The temperature dependence of the sublattice moments indicates a compensation-like crossover between Mn1- and Mn2-derived magnetization near 380 K. These findings uncover a previously unrecognized subtlety in the magnetic and structural behavior of Mn3GeN, highlighting the interplay between structural distortions, magnetic ordering, and electronic structure in kagome-derived antiperovskite materials.
@article{arxiv.2512.14571,
title = {Ferrimagnetic Order in Tetragonal Antiperovskite Mn$_3$GeN},
author = {Shaun O'Donnell and Corlyn Regier and Sharad Mahatara and H. Cein Mandujano and Efrain E. Rodriguez and Danielle R. Yahne and Stephan Lany and Sage R. Bauers and Rebecca W. Smaha and James R. Neilson},
journal= {arXiv preprint arXiv:2512.14571},
year = {2025}
}