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Page 14 of 18 Deng et al. Microstructures 2023;3:2023044 https://dx.doi.org/10.20517/microstructures.2023.42

Figure 12. (A) The entropy change of Mn GaN under different hydrostatic pressures as a function of temperature [40] ; (B) isothermal
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entropy and adiabatic temperature changes [41] .
Matsunami et al. further suggests that the magnitude of the barocaloric effect of Mn GaN is determined by
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the volume change at the transition and stability of the AFM phase against the pressure . In 2018,
[40]
Boldrin et al. further investigated the barocaloric effect in the geometrically frustrated antiferromagnet Mn 3
[41]
NiN [Figure 12B] . It is worth noting that a large barocaloric entropy change, which is a factor of 1.6 than
that of Mn GaN, is observed. Boldrin et al. proposed that the barocaloric effect of Mn NiN originates from
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multisite exchange interactions amongst the local Mn magnetic moments and their coupling with itinerant
electron spins .
[41]
CONCLUSION AND OUTLOOK
As reviewed in this article, owing to the magnetic frustration prompted by Mn N or Mn C octahedra,
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antiperovskites display the abounding magnetic structures, including collinear AFM, collinear FM, collinear
FIM, non-collinear magnetic and non-coplanar magnetic spin configurations. In antiperovskites, the
magnetic phase transition (magnetic structures), abnormal lattice change, and electronic transport
properties are interrelated and affect each other, showing a large number of physical properties such as
ATE, electronic transport properties, piezomagnetic/baromagnetic effects, magnetocaloric effect,
barocaloric effect, etc. Therefore, antiperovskites will be an excellent candidate for exploring new smart
materials. In order to further optimize performance and explore mechanisms, the following issues for in-
depth research deserve attention and solutions:

Exploration of new magnetic structures. The examination of new physical properties is one of the important
directions of the development of modern smart materials. Due to the strong correlation of "lattice-spin-
charge", antiperovskites show a series of rich and unique physical properties within some specific magnetic
structures. Although the determination of the magnetic structures is a central issue in antiperovskites, there
is still a lack of systematic and in-depth research, especially on how the magnetic structures and correlated
physical properties evolve in the case of elemental doping, variated temperatures, varied magnetic fields,
and pressurization.

Synthesis of single crystal samples. The current research work on antiperovskites is mainly focused on
polycrystalline. From the perspective of mechanism research and application, single crystal research has
greater advantages. However, it is difficult to precisely control the nitrogen/carbon contents of
antiperovskites in preparation, and the change of contents has a great influence on its physical properties.
Therefore, the synthesis of three-dimensional single crystal materials with excellent physical properties is
challenging.