MnSiN2 is a transition metal nitride with Mn and Si ions displaying an ordered distribution on the cation sites of a distorted wurtzite-derived structure. The Mn2+ ions reside on a 3D diamond-like covalent network with strong superexchange pathways. We simulate its electronic structure and find that the N anions in MnSiN2 act as σ- and π-donors, which serve to enhance the N-mediated superexchange, leading to the high N\'{e}el ordering temperature of TN = 443 K. Polycrystalline samples of MnSiN2 were prepared to reexamine the magnetic structure and resolve previously reported discrepancies. An additional magnetic canting transition is observed at Tcant = 433 K and the precise canted ground state magnetic structure has been resolved using a combination of DFT calculations and powder neutron diffraction. The calculations favor a G-type antiferromagnetic spin order with lowering to Pc′. Irreducible representation analysis of the magnetic Bragg peaks supports the lowering of the magnetic symmetry. The computed model includes a 10∘ rotation of the magnetic spins away from the crystallographic c-axis consistent with measured powder neutron diffraction data modeling and a small canting of 0.6∘.
@article{arxiv.2308.04558,
title = {Canted Antiferromagnetism in Polar MnSiN$_2$ with High N\'eel Temperature},
author = {Linus Kautzsch and Alexandru B. Georgescu and Danilo Puggioni and Greggory Kent and Keith M. Taddei and Aiden Reilly and Ram Seshadri and James M. Rondinelli and Stephen D. Wilson},
journal= {arXiv preprint arXiv:2308.04558},
year = {2023}
}