Exploring new phases of Fe_3−xCo_xC for rare-earth-free magnets

Synergistic computational and experimental discovery of novel magnetic materials

“…CoC, schematically shown in Fig.15 A, and the simulated XRD pattern based on the theoretical structural model is in good agreement with the experimental data as shown in Fig.15B 99. …”

“…Appreciable magnetocrystalline anisotropies, around 10 Mergs/cm 3 , have been measured in some metastable carbide phases including Fe 2 CoC. 98,99 In addition, the AGA helped to identify the atomic structural model of the Pnma phase for The AGA has predicted new Fe 3 S structures with formation energies lower than that of the experimentally reported Pnma structure as shown in Fig. 16A.…”

“…theoretically and experimentally to discover suitable magnetic compounds with high anisotropy and high magnetization. 15,[97][98][99][100] Besides reproducing the known Fe 3 C compound with cementite (Pnma) structure, the AGA search also has captured several new metastable phases. 99 In particular, a bainite (P6 3 22) structure exhibits the largest magnetic moment among all the structures in the Fe 3 C pool and its energy is only 4 meV higher than the low-energy cementite (Pnma) phase.…”

“…15,[97][98][99][100] Besides reproducing the known Fe 3 C compound with cementite (Pnma) structure, the AGA search also has captured several new metastable phases. 99 In particular, a bainite (P6 3 22) structure exhibits the largest magnetic moment among all the structures in the Fe 3 C pool and its energy is only 4 meV higher than the low-energy cementite (Pnma) phase. Appreciable magnetocrystalline anisotropies, around 10 Mergs/cm 3 , have been measured in some metastable carbide phases including Fe 2 CoC.…”

New methods and typical applications of crystal structure prediction

“…B, C, N等轻元素来增加其稳定性 [30] . 针对这个思路, 研究人员通过AGA晶体结构预测以及第一性原理计 算, 系统研究了Fe 3−x Co x C等组分的结构、磁矩和磁晶 各向异性能 [31] . 除了验证已知的Fe 3 C (Pnma)结构之 图 5 (网络版彩图)四面体结构产生的示意图 [36] .…”