Results for “Mn3GeN” | Engineering Papers

DOE OSTI2020

Materials Data on Mn3GeN by Materials Project

Mn3GeN crystallizes in the tetragonal I4/mcm space group. The structure is three-dimensional. there are two inequivalent Mn sites. In the first Mn site, Mn is bonded in a distorted bent 150 degrees geometry to two equivalent Ge and two equivalent N atoms. Both Mn–Ge bond lengths are 2.46 Å. Both Mn–N bond lengths are 1.91 Å. In the second Mn site, Mn is bonded in a distorted linear geometry to four equivalent Ge and two equivalent N atoms. All Mn–Ge bond lengths are 2.62 Å. Both Mn–N bond lengths are 2.03 Å. Ge is bonded in a 12-coordinate geometry to eight Mn atoms. N is bonded to six Mn atoms to form corner-sharing NMn6 octahedra. The corner-sharing octahedra tilt angles range from 0–29°.

36 MATERIALS SCIENCE↗

DOE OSTI2026

Ferrimagnetic Order in Tetragonal Antiperovskite Mn3GeN

The crystal and magnetic structures of the nitride antiperovskite M⁢n3⁢GeN reveals ferrimagnetic order stemming from a distorted kagome-derived lattice of the Mn atoms. Polycrystalline M⁢n3⁢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 (M⁢n3⁢Ge⁢N0.992⁢(7)) adopting a tetragonal 𝐼⁢4/𝑚⁢𝑐⁢𝑚 structure at 𝑇=500K and below, featuring axially distorted and tilted [NM⁢n6] 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 𝑃⁢𝑚⁢3⁢𝑚 antiperovskite phase at 𝑇≈527K. Neutron diffraction and magnetometry together reveal noncollinear ferrimagnetic ordering. For 30K≤𝑇≤500K, the magnetic structure is described by magnetic space group 𝐼⁢𝑏⁢𝑎′⁢𝑚′ (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 M⁢n3⁢GeN, highlighting the interplay between structural distortions, magnetic ordering, and electronic structure in kagome-derived antiperovskite materials.

36 MATERIALS SCIENCE↗