LAUSR

Using a crystal structure prediction program (CALYPSO), we found many experimentally synthesizable low-energy structures with perfect or nearly perfect easy-axis magnetocrystalline anisotropy energy (MAE) in manganese nitride, including MnN, Mn2N, Mn3N2, Mn5N2, and Mn4N, respectively, which are the stoichiometries more frequently studied by experimental researchers. MnN ( I4―2d ) shows giant MAE with values of E 001 = 1006, E 010 = 0, and E 100 = 920 μeV/atom (same hereafter in the abstract for the MAE unit). Mn3N2 (P42/mmc) shows perfect easy-axis MAE, whose E 010 = E 100 = 12, whereas Ibam has a nearly perfect easy-axis MAE with values of E 001 = 324 and E 010 = 345. Mn2N has four almost totally perfect easy-axis MAE structures, including P4/mmm (E 001 = 249, E 100 = 250), Pccm (E 001 = E 100 = 62), P4/nmm (E 001 = 58, E 100 = 60), and Imma (E 001 = 108, E 100 = 109). Mn4N has one perfect structure, I4/mmm (E 001 = E 100 = 169), and two nearly perfect structures, including Fmmm (E 001 = 126, E 010 = 121) as well as I4/mmm (E 010 = 127, E 100 = 133). Too many valuable structures deserve to be further studied by both theoretical and experimental scientists regarding their other magnetic properties except for the present MAE. The present study might attract close attention to several of these compounds.