The crystal and magnetic structures of the nitride antiperovskite $\mathrm{M}{\mathrm{n}}_3\mathrm{GeN}$ reveals ferrimagnetic order stemming from a distorted kagome-derived lattice of the Mn atoms. Polycrystalline $\mathrm{M}{\mathrm{n}}_3\mathrm{GeN}$ 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 ($\mathrm{M}{\mathrm{n}}_3\mathrm{Ge}{\mathrm{N}}_{0.992\left(7\right)}$) adopting a tetragonal $I4/mcm$ structure at $T=500\mathrm{K}$ and below, featuring axially distorted and tilted $\left[\mathrm{NM}{\mathrm{n}}_6\right]$ 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 $Pm\overline{3}m$ antiperovskite phase at $T\approx 527\mathrm{K}$. Neutron diffraction and magnetometry together reveal noncollinear ferrimagnetic ordering. For $30\mathrm{K}\le T\le 500\mathrm{K}$, the magnetic structure is described by magnetic space group $Ib{a}^{\prime }{m}^{\prime }$ (72.544), with inequivalent Mn1 and Mn2 sublattices that couple antiferromagnetically to yield a net moment. Density-functional theory-based calculations show that the different local moments originate from the bandwidths associated with distinct Mn–N bond lengths. Temperature-dependent refinements reveal distinct differences in the thermal disordering profiles of the Mn1 and Mn2 sublattices. These findings reveal a subtlety in the magnetic and structural behavior of $\mathrm{M}{\mathrm{n}}_3\mathrm{GeN}$, highlighting the interplay between structural distortions, magnetic ordering, and electronic structure in kagome-derived antiperovskite materials.

Close

PrevNext

View figure in article

• Composition
• Ferrimagnetism
• Magnetic order
• Magnetic susceptibility
• Magnetism
• Crystal structures
• Polycrystalline materials
• Crystallography
• Density functional theory
• First-principles calculations
• Neutron diffraction