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Page 6 of 18 Deng et al. Microstructures 2023;3:2023044 https://dx.doi.org/10.20517/microstructures.2023.42

Figure 6. The non-coplanar FIM structures of (A) Mn Cu N [39] , (B) Mn Ga N [35] , (C) Mn SbN [61] , and (D) Mn Co N [62] .
3 0.89 0.96 3 0.95 0.94 3 3.39 0.61
~353 K and FIM-M2 phase transition at ~250 K. Neutron diffraction pattern at 300 K reveals the non-
collinear FIM phase with a sub-lattice a, a, 2c where a and c are the lattice parameters of the tetragonal
nuclear structure. The Mn atoms are located at six different types of sites with a P4 space group. Mn1 (0.5,
0.5, 0) and Mn2 (0.5, 0.5, 0.5) display the FM component 2.5 μ /Mn along the z axis. Moreover, the tiled
B
magnetic moments were uncovered for Mn3 (0.5, 0, 0.25), Mn4 (0, 0.5, 0.25), Mn5 (0.5, 0, 0.75), and
Mn6 (0, 0.5, 0.75), corresponding to (−2.47, 2.47, −2.16) μ /Mn, (2.47, −2.47, −2.16) μ /Mn, (2.47, −2.47,
B
B
−2.16) μ /Mn, and (−2.47, 2.47, −2.16) μ /Mn, respectively. At 5 K, another non-coplanar magnetic structure
B
B
M2 with a was revealed in Mn SbN. Herein, Mn atoms on the plane z = 0.5 show a “square” AFM
3
arrangement with the moment 2.3 μ /Mn, while the other Mn atoms display the AFM component along the
B
z axis with the moment 2.5 μ /Mn. The minor differences between the presented magnetic structure and the
B
[54]
previously reported one may arise from the tiny elemental components . Even more interesting in
antiperovskites is that the propagation vector k = (0, 0, k ) of Mn SnN varies with temperature from k = 0.25
3
z
z
[54]
at 50 K to k = 0.125 at 237 K .
z
The effect of magnetic element doping on the magnetic structure was also investigated in antiperovskites.
For Mn-doped Mn Ni N and Mn Co N compounds [Figure 6D], a FM component along the [111]
3.39
1-x
0.61
3+x
direction coexisting with canted Γ AFM component was resolved by neutron diffraction technique [15,62] .
5g
Table 1 summarizes the magnetic structures and corresponding temperature ranges of typical
antiperovskites.
PHYSICAL PROPERTIES OF ANTIPEROVSKITES
The research on antiperovskite structure compounds can be traced back to the 1930s when there were not
many studies on physical properties. Since the 1980s, this type of compound has been paid attention by
scientists, and the basic physical properties of antiperovskites have been studied by means of neutron
diffraction, X-ray diffraction (XRD), Mössbauer spectroscopy, and nuclear magnetic resonance. Extensive
research of these basic physical properties mainly includes crystal structures, magnetic properties (magnetic
structures), phase diagrams, etc. At the beginning of the 21st century, superconductivity, giant
magnetoresistance, magnetocaloric effect, abnormal thermal expansion, and near-zero temperature
coefficient of resistance behaviors were successively reported in antiperovskites. The discovery of these
physical properties prompted more and more researchers to pay attention to antiperovskites and their