Database statistics:

A total of 3,826 entries, including 300+ Fe-based rare-earth-free magnets discovered through our adaptive genetic algorithm (AGA) searches, are registered in our database. Data statistics are summarized here.

Phase diagrams:

Binary phases: Fe-N (38 entries), Fe-S (45 entries), Fe-Si (47 entries), Co-N (183 entries), Zr-Co (42 entries), among others.
Ternary phases: Fe-Co-N (272 entries), Fe-Co-S (34 entries), Zr-Co-B (50 entries), Zr-Co-C (55 entries), Zr-Co-N (79 entries), among others.

Benchmark test:

Benchmark results are summarized here, where we compare theoretical and experimental values.
random selection: Fe-N (38 entries found)
Displaying 19 entries out of 19 entries found.
Crystallographic data Sstructural stability [Footnotes] Magnetic properties [Footnotes, magnetic units] Methods References
Materials ID Formula Formula units per cell Atomic sites per cell Crystal system Space group [Number] Formation energy (eV/atom) Energy relative to convex hull (eV/atom) Structure search Averaged magnetic moment (μB/atom) Magnetic polarization, Js (T) Magnetic easy axis Magnetic anisotropy constants:
Ka-c, Kb-c, Kb-a, Kd-a (MJ/m3)		 Curie temperature, TC (K) Methods References
MMD-819 Fe3C 2 8 hexagonal P6_322 [182] 0.861 0.861 AGA search 1.81 1.52 ab plane -0.20 . . . . DFT MS
MMD-820 Fe3C 4 16 orthorhombic Pnma [62] 0.495 0.495 AGA search 1.87 1.85 a -0.73 1.06 1.80 . . DFT MS
MMD-821 Fe3C 4 16 orthorhombic Pnma [62] 0.545 0.545 AGA search 1.77 1.59 a -1.58 0.15 1.73 . . DFT MS
MMD-822 Fe3C 4 16 orthorhombic Pnma [62] 0.352 0.352 AGA search 1.78 1.82 a -1.16 0.30 1.47 . . DFT MS
MMD-823 Fe3C 2 8 hexagonal P6_322 [182] 0.579 0.579 AGA search 1.78 1.59 c 0.11 . . . . DFT MS
MMD-1053 Fe4C 2 10 tetragonal I4/m [87] 0.242 0.242 MP 0.00 0.00 . . . . . . DFT mp-1070333
MMD-1060 Fe4C 2 10 monoclinic P2_1/m [11] 0.101 0.101 MP 1.49 1.75 c 0.12 0.06 -0.07 . . DFT mp-1078579
MMD-1097 Fe23C6 4 116 cubic Fm-3m [225] 0.022 0.022 MP 1.60 1.89 . . . . . . DFT mp-1192884
MMD-1103 Fe3C 8 32 tetragonal I-42m [121] 0.125 0.125 MP 1.40 1.75 c 0.45 . . . . DFT mp-1205436
MMD-1104 Fe3C 8 32 monoclinic C2/m [12] 0.121 0.121 MP 1.22 1.49 b -0.08 -0.21 -0.13 . . DFT mp-1205444
MMD-1155 Fe4C 1 5 cubic P-43m [215] 0.479 0.479 MP 1.66 1.71 <111> . . . -0.42 . DFT mp-1246
MMD-1156 Fe3C 2 8 hexagonal P6_322 [182] 0.016 0.016 MP 1.48 1.69 c 0.48 . . . . DFT mp-13154
MMD-1169 Fe7C3 2 20 hexagonal P6_3mc [186] 0.036 0.036 MP 1.18 1.51 c 0.22 . . . . DFT mp-18257
MMD-1172 Fe2C 2 6 orthorhombic Pnnm [58] 0.006 0.006 MP 1.07 1.32 a -1.01 0.29 1.30 . . DFT mp-1871
MMD-1197 Fe7C3 4 40 orthorhombic Pnma [62] 0.021 0.021 MP 1.20 1.53 a -0.26 0.26 0.53 . . DFT mp-21717
MMD-1213 Fe5C2 4 28 monoclinic C2/c [15] 0.017 0.017 MP 1.20 1.52 a -1.17 -0.91 0.26 . . DFT mp-2794
MMD-1222 Fe3C 4 16 orthorhombic Pnma [62] 0.020 0.020 MP 1.39 1.70 c 0.24 1.01 0.77 . . DFT mp-510623
MMD-1246 Fe3C 4 16 orthorhombic Pnma [62] 0.083 0.083 MP 1.42 1.60 b 0.12 -0.63 -0.75 . . DFT mp-613523
MMD-1253 Fe5C2 4 28 monoclinic P2/c [13] 0.019 0.019 MP 1.22 1.53 b 0.67 -0.09 -0.76 . . DFT mp-645339
Footnotes:
  1. Formation energy:
    We perform DFT calculations to calculate the total enegies of all the structures. The formation energy is computed with respect to a linear combination of the total energies of reference elemental phases. When the formation energies are plotted as a function of chemical composition, a set of stable compounds forms a convex hull, which represents a boundary (theoretical lower limit) in a compositional phase diagram. Metastable compounds lie above the hull, and the energy relative to the hull (distance to the hull) is a useful quantity to examine the metastability of a new compound. The lower the formation energy above the convex hull, the more likely it is for the material to exist.
  2. Magnetic anisotropy constants:
    Magnetic anisotropy constant, Ka-c, is defined as Ka-c = Ea-Ec, where Ea and Ec are the total energies per volume for the magnetization oriented along the crystallographic a and c axes, respectively. Similarly, Kb-c and Kb-a are defined as Kb-c = Eb-Ec and Kb-a = Eb-Ea, respectively. For cubic crystal systems, magnetic anisotropy constant is calculated as Kd-a = Ed-Ea, where Ed is the total energy per volume for the magnetization oriented along the body-diagonal direction of the unit cell.
Collaborative PIs:
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